Handling Databases with Research Advance Imaging The table can be created in two ways: Creating table through Design View tab Field Name Data Type EmployeeID Autonumber FirstName Short Text LastName Short Text Address-1 Short Text Address-2 Short Text City Short Text State Short Text Zip Short Text Phone Short Text Phone Type Short Text 1. Right click Table 1 in the navigation pane and select Design View . 51 The City School 2023-2024
2. Access will prompt you to save the table first. Enter a suitable name for your table. 3. Once in Design View, enter the field name and its respective data type. Once we type the field name MS Access will automatically assign the short text data type to the field which can be modified as per our requirement from the drop-down menu. 4. Switch to Datasheet View to have look at your table. It is important to save your table at this stage. 52 The City School 2023-2024
Handling Databases with Research Advance Imaging 5. The ID field is created in every table by default. To change the name of the ID field to EmployeeID, click Name and Caption option. Creating table through Datasheet View You can directly enter table field name from the datasheet view in Access. 1. To add a new field, double click Click to Add button on the table. 2. Once you double click Click to Add, a drop down list will appear, prompting you to select the datatype for your field. For the present example, select Short Text. 53 The City School 2023-2024
3. After selecting the data type, enter the required field name. Enter FirstName as the field name for the given example. 4. After entring the field names, you can now enter records in the table. 3.6. Creating Relationships Between Tables MS Access uses table relationships to join tables when you need to use them in a database object. There are several reasons why you should create table relationships before you create other database objects, such as forms, queries and reports. Facebook uses MySQL as primary database management systems for data storage such as wall posts, information of users, their timeline and so on. MS Excel is used to make graphs, charts, histograms and perform complext calculations where as MS Access is database management tool, used to store and manipulate data. Excel vs Access 54 The City School 2023-2024
Handling Databases with Research Advance Imaging Primary Key • To work with records from more than one table, you often must create a query that joins the tables. • The query works by matching the values in the primary key field of the first table with a foreign key field in the second table. • When you design a form or report, MS Access uses the information it gathers from the table relationships you have already defined to present you with informed choices and to prepopulate property settings with appropriate default values. A primary key, also called a primary keyword, is a key in a database that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). A relational database must always have one and only one primary key. Primary keys typically appear as columns in relational database tables. Foreign Key A foreign key is a column or group of columns in a relational database table that provides a link between data in two tables. It acts as a cross-reference between tables because it references the primary key of another table, thereby establishing a link between them. 55 The City School 2023-2024
In a database when we define any field as a Primary Key (PK) there are two rules or constraints applied to that field automatically. Not Null: this constraint enforces that this field cannot be left unused. In Database terminology, NOT NULL is not considered as empty or zero, it just defined as the data has not been entered yet. Unique: this constraint enforces that the data entered in this field cannot be repeated or all the values entered should be unique to each other. When you design a database, you divide your information into tables, each of which has a primary key and then add foreign keys to related tables that reference those primary keys. These foreign key-primary key pairings form the basis for table relationships and multi-table queries. 3.7. Constraints in Database Checkpoint Rows are also called records Databases are structured set of data. Columns are also called fields 56 The City School 2023-2024
Handling Databases with Research Advance Imaging For creating relationships in our database, we need another table and will name it tblHRData using Table Design as shown in the image. Make sure to select the relevant data type according to fields. 3.8. Creating Relationships in MS Access Now we will work with One-to-One Relationship in MS Access. This relationship is used to relate one record from one table to one and only one record in another table. 1. Go to the Database Tools tab, click on the Relationships option. 2. Select tblEmployee and tblHRData holding the shift key and then click on the Add button to add them to our view and then close the Show Table dialogue box. 3. To create a relationship between these two tables, use the mouse, and click and hold the EmployeeID field from tblEmployee and drag and drop that field on the field we want to relate by hovering the mouse right over EmployeeID from tblHRData. 4. When you release your mouse button, Access will then open the Edit Relationships window. 57 The City School 2023-2024
5. This window relates EmployeeID of tblEmployee to EmployeeID of tblHRData. Now click on the Create button and now these two tables are related. 6. The relationship is now saved automatically and there’s no need to click on the Save button. Now that we have the most basic of relationships created, let us now go to the table side to see what has happened with this relationship. 7. Open and enter 5 random records of an employee in tblEmployees table. Here, on the left-hand side of each record, you will see a little plus sign by default. When you create a relationship, Access will automatically add a sub-datasheet to that table. 3.9. Simple and Complex Queries in MS Access Database tables can hold a lot of records, in some cases, millions or billions of them. Queries allow you to pull information from one or more tables based on a set of search conditions that you define. A query is a special “question” you apply to the database to find specific data and get the information you want. For this task, let’s continue working with the Employee table we have used before. 58 The City School 2023-2024
Handling Databases with Research Advance Imaging Planning a Query Pinpoint Identify When planning a query that uses more than one table, you should go through these four steps: Knowing precisely what question you want to answer is essential to building a useful query. Know the fields that you need to include in your query and the tables they are contained in. Know the criteria the information in each field needs to meet and the information you need to display. Know every type of query result you want included in your query results. Locate Determine 59 The City School 2023-2024
Example 1: For this task, let’s continue working with the Employee table we have used before. Let us suppose that we need the data of our employees with their first name, last name and their salaries which are higher than 3500$. 1. Click on the Query Design option from the create tab. 2. A new window will open with the name of Show Table. 3. Select and add tbleEmployee and tblHRData. 4. For the first column select the employee’s first name. 5. In the second column select employee’s last name. 6. In the third column select StartSalary. 7. We can get the data from both tables accurately as both table’s EmployeeID fields are related to each other using PK and FK. 8. After selecting the fields for a query, you can see the name of fields and other options for Sort and setting a criterion. 9. Select the Ascending option from the first column (FirstName). Creating Queries in MS Access Pinpoint Employees who earn more than $3500 Identify FirstName, LastName, StartSalary Locate tblEmployee (EmployeeID, FirstName, LastName) tblHRData (StartSalary) Determine StartSalary>$3500 60 The City School 2023-2024
Handling Databases with Research Advance Imaging Example 2: Assume that we need the list of employees who have joined after the year 2018. 1. Add the preferred columns along with the field of HireDate from tblHRData. 2. And enter the criteria as >12/30/2018 and press enter. 3. Save the query with an appropriate name. 4. You will see list of employees who have joined after 2018. 10. In the third column enter the criteria for salaries as preferred. In the example, we have entered >3500. Which means that employees who have salaries greater than 3500 will be listed in ascending order after executing the queries. 11. Save the query by using the right click on the query tab and save it with any preferred name. In the example, we have saved the query with the name of Salaries Greater than 3500. 12. Close the tab and run the query from the objects panel. Pinpoint Employees who joined after 2018 Identify FirstName, LastName, HireDate Locate tblEmployee (EmployeeID, FirstName, LastName) tblHRData (HireDate) Determine HireDate>12/30/2018 61 The City School 2023-2024
Example 3: For this example, lets suppose we want to sort employees based on a specific city based on user input. 1. In order to take user input, the query design should look like this. 2. Save and run the query and this time you will observe a 3. dialogue box will appear asking parameters. 4. Enter the name of the city in the dialog box and press OK. 5. The results would appear based on the input specified. 3.10.Forms and Reports in MS Access Forms in Access are like display cases in stores that make it easier to view or get the items that you want. MS Access is not just a database software, it also gives us the liberty to use it as a software solution for business organizations, and to fulfil this purpose using forms are one essential part where a user can access or enter the relevant records in a database. Since forms are objects through which you or other users can add, edit, or display the data stored in your Access desktop database, the design of your form is an important aspect. Checkpoint Unique constraint enforces that the data in the field cannot be repeated. Not Null enforces that field cannot be left unused. Forms in MS Access 62 The City School 2023-2024
Handling Databases with Research Advance Imaging There are a few methods you can use to create forms in Access. One of the easiest ways to create a form is with a wizard. 1. Open your دatabase and go to the Create tab. In the Forms group, in the upper righthand corner, you will see the Form Wizard button. 2. Click on that button to launch the Form Wizard 3. On this first screen in the wizard, you can select fields that you want to display on your form, and you can choose from fields from more than one table or a query. 4. Let us assume we want to simply have a quick form that we are going to use for data entry for our employee information. 5. From the Tables/Queries drop-down list, select tblEmployees table. Click on the double arrow to move all the fields at once and click next. 6. After clicking next, the Form Wizard will ask for the layout that we would like for our form. We have the columnar, tabular, datasheet and justified layouts. We will choose the columnar layout here and then click Next. 7. On the next windows we need to give a title to our form i.e. EmployeeForm. Creating Forms 63 The City School 2023-2024
8. Once you have given your form a title, there will be two more options below by which you can open the form to see what that form looks like, or you can begin entering information into your table. 9. You can choose the option to modify the form’s design. 10. Choose the first option to open the form to view or enter information and click Finish. 11. Take a look at the following image. This is what form looks like. 12. This is a single item form, meaning one record is displayed at a time and further down you can see the navigation buttons , which is telling us that this is displaying the record 1 of 5. 13. If you click on button it will move to the next record. 14. If you want to jump to the very last record in that form or that table, use the button right beside that right arrow that’s the last record button. 15. If you want to add new employee information, press button to add a record. Reports in MS Access Reports offer a way to view, format, and summarize the information in your Microsoft Access database. For example, you can create a simple report of phone numbers for all your contacts. 1. Open your Database and go to the Create tab. In the report group, in the upper right-hand corner, you will see the Report Wizard button. 2. Click on that button to launch the Report Wizard 3. On this first screen in the wizard, you can select fields that you want to list on your 64 The City School 2023-2024
Handling Databases with Research Advance Imaging report, and you can choose from fields from more than one table or a query. 4. You can also create reports by using the queries generated by you in printable format. 5. Let us assume we want to a report of our records which are available in two different tables. This report will consist of employee ID, First name, Last Name, city, phone and StartSalary. First five fields are from tbleEmployee and one field of StartSalary from tblHRData. 6. After adding five fields from tbleEmployee change the table to tblHRData and add StartSalary field. 7. In the next step select the by tblHRData option and click next. 8. In the next window there is an option for a grouping a record under any field, which is used for complex reports, simply click next to the sorting window. 9. In this window you can sort the fields as per the preference needed for the report and click next, options for sorting these fields are limited to four. 10. In the next window select the layout and orientation of your report as per your preference. 11. There would be a checkbox below these settings indicating “Adjust the field width so all fields fit on a page”. Keep this option checked as it will automatically adjust all the placement smartly and properly. 65 The City School 2023-2024
3.11. Import and Export Data in MS Access In MS Access we can import and export data from multiple sources like MS Excel, MS Access, Text file (delimited or fixed-width), XML, ODBC Databases (For example, SQL Server). Importing and exporting data is easy in MS Access using wizards. Checkpoint A query allows you to pull information from different tables based on a certain criteria. 12. In the next window name your report as per your preference, below this option you will see an option for preview and modification select the Preview option and click finish. 13. This would be the output of your report. 14. As you can see the Employee ID heading is somehow left out. This can be fixed using the design view mode. 15. To access the design view mode right click on the tblEmployee Report Tab and click on 2nd last option of design view. 16. From this option, you can resize the fields of First Name and Lastname a little short to adjust Employee ID field like a text box in MS Word. 17. Save and close the report and reopen it from the object menu on the left. 66 The City School 2023-2024
Handling Databases with Research Advance Imaging Importing Data in MS Access 1. Click External Data tab and select New Data Source in the import and link tab. 2. Select Excel from the list. a window will pop-up, from where you will browse the excel sheet that you want to import. 3. The import wizard has different import options. For now, select the first option and click Next. 4. The import wizard has different options. For now, select the first option. 5. The next window shows all the sheets of the excel file. Select the sheet that you want to import and click Next. 6. The next window shows all the records of the selected excel sheet. Click Next. 7. The next step is to select primary key for the table. You can either let Access select the primary key or you can select your own primary key or have no primary key at all. For now, select the first option and click Next. 8. Click Finish. 67 The City School 2023-2024
Exporting Data from MS Access 1. Go to External Data Tab and click on the Text icon. 2. Select the file name of the location to save the text file. 3. In the next window, Access will show the preview of the text file and also show the two options to select the format within. 4. In the next window, Access will give the option to segregate data using different text qualifiers. Select your preferred qualifier and click next. The most common used qualifier is a comma. 5. At this step Access will reconfirm the file name and its location on your computer. 6. Click finish if there are no changes required. 7. This data can be used in other software using Text or CSV format importing. 3.12. Microsoft Forms Microsoft Forms allows Office 365 users to create custom surveys, quizzes, polls and questionnaires in minutes. It is a great way to ask quick questions and receive feedback or conduct an in-depth survey with up to 5000 responses. Microsoft Forms allows the content created to be sent as an invitation to other users and be filled out on any O365 compatible device. The creator can see realtime results and use inbuilt statistics or export the data for further analysis. Checkpoint Forms allow to dd, edit, or display the data stored in database. Reports allow to view, format, and summarize the information database. 68 The City School 2023-2024
Handling Databases with Research Advance Imaging 1. Open a web browser and go to https://forms.office.com/ 2. Log in with your email address and password. Accessing Forms Creating a New Form 1. From the Forms home page click New Form, which opens a blank form. 2. Click Untitled form to edit the title and add a description. 3. The form auto-saves, a save indicator in the top left corner confirms when completed. 4. Click Add New to create content. 5. Choose the type of question: Multiple Choice, Text, Rating, Date or Ranking. 6. Fill in required fields for the selection – available options will change depending on the question chosen. 69 The City School 2023-2024
Adding Media to Form Sharing the Form 1. Click Media to add media (image or video) to a question. 2. Select Image or Video. 3. To add an image, you can select image directly from web, from your OneDrive folder or upload from your computer 4. To add video, click the video option. 5. Paste the YouTube URL (web address) of the video into the URL box (this works with Private, Unlisted and Public YouTube videos). 6. Click Add. Once complete, use the toolbar options to preview, add a theme or share the form. Preview the form to see how it looks on a computer or mobile device. Select a colour or theme to apply to the form or upload a custom banner image. Share the form with the participants and choose sharing settings 70 The City School 2023-2024
Handling Databases with Research Advance Imaging 1. Click Share from the Form toolbar 2. Choose an audience from the dropdown menu. 3. Forms sent to people within organization can be set to record the person’s name, forms sent to external email addresses will only record the respondents name as anonymous. 4. To generate a link for the form, click Copy next to the link box, this link can be emailed or sent as a message. Once you have created the form and shared with the required audience, it is important to view the responses of the participants for analysis puroses. You can view the responses of participants by clicking on the Responses tab on the top of the form. The responses tab gives you a complete view of the results of your form. To share the form: View Form Responses There are three options for sharing forms 1. Send and collect responses 2. Share as a template 3. Share to collaborate 71 The City School 2023-2024
Responses show the number of participants who responded. Average time taken by the participants to complete the form. Active shows that the form is still actively accepting responses. View results of each individual participant. Analysis of the responses recorded. View the results of form in excel sheet View Saved Forms To view saved Forms or Forms you have been granted edit access to, go to https://forms.office.com. Once you sign-in, you can view all the saved forms and the forms that are shared with you. The responses tab gives you the following information. 72 The City School 2023-2024
1. A structured set of data held in a computer that is accessible in various ways is called Database. 2. Tables are composed of horizontal rows and vertical columns, with small rectangles called cells. 3. Field is a way of organizing information by type. Whereas, A record is one unit of information. 4. A primary key in a database uniquely idenfies each record. 5. A foreign key is a column or group of columns in a relational database table that provides a link between data in two tables. 6. Not null constraint enforces that this field cannot be left unused. 7. Unique constraint enforces that the data entered in this field cannot be repeated or all the values entered should be unique to each other. 8. A query is a special question you apply to the database to find specific data and get the information you want. 9. Forms allow to add, edit or display the information stored in the database 10. Reports allow you to view, format and summarize the information database. 11. Microsoft Forms allows Office 365 users to create custom surveys, quizzes, polls and questionnaires. Let’s Review My Notes! 73 The City School 2023-2024
Most Downloaded Apps of 2020 TikTok Instagram Snapchat Google Meet Netflix WhatsApp Facebook 850 Million Downloads 503 Million Downloads 281 Million Downloads 254 Million Downloads 477 Million Downloads 404 Million Downloads 600 Million Downloads 540 Million Downloads Zoom Messenger 223 Million Downloads
Student Learning Outcomes ISTE Student Standard Coverage 1. Understand characteristics of good UI design 2. Familiarize with user-interface and IDE of visual studio 3. Use control elements and edit its properties 4. Understand the use of variables and common data types 5. Understand conditional and looping statements 6. Understand what events and mouse events and its types 7. Understand public and private functions 8. Understand what are modules in VS 9. Create a module using Subroutines 10. Understand the use of comments 11. Understand what error handling and its importance After going through this chapter, students will be able to: Empowered Learner Computational Thinker Creative Communicator Innovative Designer 1a 1d 4c 5d 6b 6c 6d Developing Applications
4.1. What is User Interface Design 4.2. Characteristics of Good User Interface The user interface is the graphical layout of an application. It consists of the buttons users click on, the text they read, the images, sliders, text entry fields, and all the rest of the items the user interacts with. This includes screen layout, transitions, interface animations and every single microinteraction. Any sort of visual element, interaction, or animation must all be designed. Clear Consistent A good interface makes it easy for users to tell the computer what they want to do, for the computer to request information from the users, and for the computer to present understandable information. Clear communication between the user and the computer is the working premise of good UI design. A clear interface helps prevent user errors, makes important information obvious, and contributes to ease of learning and use. If people can’t figure out how your application works or where to go on your website they’ll get confused and frustrated. The tooltip feature can give information about the tool A clear interface helps prevent user errors, makes important information obvious, and contributes to ease of learning and use. Google search Google Images 76 The City School 2023-2024
Developing Applications Error Simple Direct Responsive Attractive The best interface designs are simple. Simple designs are easy to learn and to use and give the interface a consistent look. Good design requires a good balance between maximizing functionality and maintaining simplicity through progressive disclosure of information. Users must see the visible cause-and-effect relationship between the actions they take and the objects on the screen. This allows users to feel that they are in charge of the computer’s activities. Responsive also means the interface provides some form of feedback. The interface should talk back to the user to inform them about what’s happening. Every visual element that appears on the screen potentially competes for the user’s attention. Provide an environment that is pleasant to work in and contributes to the user’s understanding of the information presented. Google search 77 The City School 2023-2024
4.3. Bad User Interfaces A user interface that doesn’t follow the guidelines for good user experience can cause frustration or even hours of missing productivity depending on the importance of the program’s job. Bad user interfaces: • Not adaptable to different kinds of screen and do not provide appropriate feedback i.e. they are unresponsive. • Have clumsy layout. Although it is important to make the design attractive to the eyes, but more importantly, it has to be functional. • Lack proper navigation. • Possess illegible text and font styles that make it difficult for the user to read and interact with the content. 78 The City School 2023-2024
Developing Applications 4.4. Getting Started with Visual Studio Writing Your First Program in VS This chapter focuses on the use of Microsoft Visual Studio IDE (integrated development environment), it is used to develop computer programs, as well as websites, web apps, web services and mobile apps. Let’s start by creating windows form program using visual studio IDE: 1. Open visual studio and click New Project, select Windows Form Application and type the name of the program. 2. On the lower right of the screen, you can see the Properties panel which allows you to define various properties of the currently selected element on the design view. Some commonly used properties are: the Text Property which defines the title of the selected element, the Name Property which defines a name with which we can refer to the selected element in our program’s code and the Enabled Property which defines if the selected element will be usable or disbaled. 79 The City School 2023-2024
3. The form we have created is currently empty and to make it purposeful we add elements called Controls. 4. To access these controls, place the mouse cursor on the extreme left of the screen where Toolbox is written and click on the pin icon to show the toolbox panel permanently. Drag and drop a button and label from toolbox on to the form. 5. Select the button and change the text to “Say Hello World” from properties panel on the right. Then scroll down the properties panel and in Design section change the (Name) to btnReaction 80 The City School 2023-2024
Developing Applications 6. Do the same with label properties and change the name with lblReaction. 7. Designing of form layout is complete now we will program the control Button so when we click the button it will trigger the command to show the text in the Label control. 8. Double click on the Button control and a script window will appear where there is a lot of code already present relative to the button functionality, although we want this button to trigger our desired text in the Label control. 9. Click on the debug button or F5 to execute the program in debugging mode. If there is an error in the program it will show the warning/problem or else the program will execute. 81 The City School 2023-2024
10. The program window will appear and if you click the Say Hello World button, the label’s text changes to Hello world! Exactly as we have programmed. Each time you test your program by clicking the Start Debugging button, an application executable file is created in ...\Projects\[project name]\[project name]\ bin\Debug. For example, for the First VB Form project, the .exe file can be found under ...\Projects\HelloWorldApplication\HelloWorldApplication\bin\Debug\ HelloWorldApplication.exe. 4.5. Basic GUI Controls in Visual Basic Button Label Radio Button Checkbox It is used as a standard Windows Button. In most cases, the Button Control is used to generate a click event, It is used to display some informative text on the GUI which is not changed during runtime. Radio Button is one of the popular ways of limiting the user to pick just one option. Checkboxes are similar to radio buttons in the way that they are also used in groups, however, a user can select more than one item in the group. A 82 The City School 2023-2024
Developing Applications Textbox It is used to accept textual input from the user. The user can add strings, numerical values and a combination of those. It is similar to the list but it works as a dropdown for the user. A user can click on the downwards aero on the right side and select any item This control allows the user pick the date and time via a Calendar and a clock. A variable is nothing but a name given to a storage area that our programs can manipulate. A variable is a container of data in a computer’s memory where the computer stores the different types of data and this could be numeric or text. To create and access these Variable (data containers) we name them so we can call them in our program where it is necessary. Combo Box DateTime Picker 4.6. Variables Public and Private Variables 4 2.5 “hello” “a” Public variables are variables that are accessible to the whole program. Private variables are variables that are accessible only to a certain part of the program or code. var a=1 var b=2 Public variable Private variable 83 The City School 2023-2024
It is used to accept textual input from the user. The user can add strings, numerical values and a combination of those. In visual studio, we can declare the variable by the keyword Dim which is a short form for dimension. For better understanding, we will create a program using 2 variables and calculate them to see its working. Follow these steps to create a program with variables in it: 1. Create a new form and name that form as Variables. 2. Add 2 text fields from the toolbox in the form. 3. Add 1 button from the toolbox in the form and change the text property of the button to Add from properties panel. 4. Add 1 label from the toolbox in the form and change the text property of the label to Result from the properties panel 5. Double click on the Add button and enter this code as shown in the example below. Click on the debug button or F5 to execute the program in debugging mode. 6. The = here is an assignment operator, a symbol used to assign the value on the right of the sign to the variable on the left. So here, the content of TextBox1 is stored in variable number1. 7. Note here that although whatever you write in a text box is considered as String. Visual Basic automatically converts it to a number since the variable number1 is declared as Integer. Declaring a Private Variable • The 1st and the 2nd line of code are where we have declared the variables with its data type which is an integer in this case. • In the 3rd and 4th lines, we have declared the value of a variable. In this case, we are taking the user input from the textbox. • In the 5th line, our code adds the two variables and puts the sum as text into Label1. How Does it Work? 84 The City School 2023-2024
Developing Applications Declaring a Public Variable Declaring a public variable is not different from declaring a private variable. The only difference is that the public variable is accessible from anywhere in the whole program. Follow the steps below to create a program for a simple counter by using a public variable. 1. Create a new form and save it with the name of Simple Counter. 2. Add 2 buttons from the toolbox. Change the text property of one button to Reset and set the text property of the other button to Add from the properties panel. 3. Set the name property of Reset and Add button to btnRst and btnAdd respectively. 4. Add a label from the toolbox and set the text property to Result from the properties panel. 5. Now that both elements codes are included in the script, we will create a public variable that is accessible for both buttons/elements. How Does it Work? • Reset button code which will declare the pub variable to 0. pub is the public variable Label1.Text = pub will display the text of pub variable in Label1 element. • Add button code will add 1 to the current value of the pub variable. Label1.Text = pub will display the text of pub variable in Label1 element after adding 1 every time the button is pressed. A website of browser-based HTML pages that are linked together and accessed over the Internet. Mobile apps are actual applications that are downloaded and installed on your mobile device, rather than being rendered within a browser. Mobile App vs Website 85 The City School 2023-2024
4.7. Data Types Variable Type Common language runtime type structure Value Range Boolean Boolean True or False Byte Byte 0 through 255 (unsigned) Char (single character) Char 0 through 65535 (unsgined) Date Date and Time 0:00:00 (midnight) on January 1, 0001 through 11:59:59 PM on December 31, 9999 Decimal Decimal 0 through +/ 79,228,162,514,264,337, 593,543,950,335 (+/- 7.9...E+28) with no decimal oint; 0 through +/- 7.9228162514264337593543950335 with 28 places to the right of the decimal; smallest nonzero number is +/- 0.00000000000000 00000000000001 (+/-1E-28) Integer Int32 -2,147,483,648 through 2,147,483,647 (signed) Long (long integer) Int64 -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807 (9.2... E+18) (signed) Object Object Any type can be stored in a variable of type Object String (Variablelength) String (class) 0 to approximately 2 billion unicode characters 86 The City School 2023-2024
Developing Applications 4.8. Conditional Statements If...Then Statement Programming is all about giving autonomy to the computers. Computers have limited intelligence and they can’t make decisions on their own unless we program them to take decisions. Therefore, decision making is an essential part of programming. Decision making statements allow to specify one or more conditions to be executed if the condition is determined to be true. Through decision making statements, we can write a program that will be able to respond to user input during its execution and give different results for different inputs. This process is possible with the use of conditional statements or If…Then statements Follow the steps below to create a simple program using condition statements: 1. Create a new form by dragging two labels, one button and one text box from the toolbox panel, as shown in the example. 2. Edit the first label’s text property to Enter your lucky number. 3. Change the name property of the text box to TextboxNumber. 4. Edit the button text to Try your luck and change its name to btnCheck 5. Edit 2nd label’s text property to Result and its name property to lblResult 6. Double click on the Try your luck button to open the script window. 7. Enter the code as shown. 8. Press the debug button to run the code. How Does it Work? 1. In the first line, we have declared a variable “number” as an integer. 2. In the second line, we have assigned the value of number variable to TextboxNumber which is a user input text box. 3. In the third line, we set a conditional statement that if the user input number is greater or equals to 7 then display the message “Congratulations you win!” in the “lblResult” Label element. 87 The City School 2023-2024
An other variant of the conditional statement is the If…Then…Else statement. This allows you to define instructions to be executed if the condition is false. For example, let’s say we want the previous program to display a relevant message to the user not only when the correct number is found but also when a wrong number is inserted. Add the else block in previous your code to understand how If...Then...Else statements work. If there are more than two choices to display, using the If...Then...Else statement is not enough. To provide more choices, we can use the If...Then...ElseIf statement. In the following example, we have created a program that translates a student’s score to the corresponding grade. 1. Create a new form with three labels, one text box and a button. 2. Edit the text for the first label to Enter Your Score. 3. Edit the button text to Show Grade. 4. Edit the text of the second label to Your Grade: 5. Place the third label adjacent to the second label and we will use this label If...Then...Else Statement If...Then...ElseIf Statement Follow the steps below to create the program using If…Then…Elself statement: 88 The City School 2023-2024
Developing Applications to generate the grade in it, edit the label text to Grade not generated yet and also change the name of this label to lblGrade from the properties panel. 6. Enter the code as shown in the example: How Does it Work? • The first condition score >= 90 is evaluated and if it is true, then the variable grade takes the value A. • If a condition is found true, the following conditions are not evaluated and the instructions under End If are executed. • If a condition is evaluated as false, then the next condition is evaluated and so on, until a condition is true. • If none of the conditions are found to be true, then the code under Else is executed which has a string value of “Need Improvement”. 4.9. Conditional Operators Conditional operators refine the statement you’re testing for. For instance, you can specify the statement whether it’s greater than, less than, and a whole lot more. Operator Meaning = Equal too > Greater than < Less than >= More than or equal to <= Less than or equal to <> Not equal to Checkpoint Good UI are clear, consistent, simple, direct, responsive and attractive. A variable is a name given to storage area that the programs can manipulate. 89 The City School 2023-2024
Logical Operators Logical operators are similar to Boolean expressions that return a boolean result. These operators are called binary because they acquire two operands. Operator Meaning AND Both sides must be true OR One one the two conditions must be true XOR One side or other must be true but not both NOT Negates truth 4.10. Looping Statements In computer programming, a loop is a sequence of instructions that is repeated until a certain condition is reached. An operation is done, such as getting an item of data and changing it, and then some condition is checked such as whether a counter has reached a prescribed number. In Visual Basic, we have two different structures that support repetitions, or loops as they are called in programming languages. For...Next Loop What if we want to add all the integers from 1 to 50? Of course, we are not going to start writing 1+2+3+…, we are going to program the computer to do the same thing using loops. Follow the steps below to create a program using Loops. 1. Create a new form. Drag two labels and one button from the toolbox panel and place on the form. 2. Set the text property of first label to 1+2+3+...+50: 3. Set the text property of the second label to result and set its name property to lblResult. As of 1st quarter 2020, Google Play store contains 2.9 million apps, while Apple AppStore is the second-largest app store with approximately 1.85 million available apps for iOS. 90 The City School 2023-2024
Developing Applications 4. Set the text property of the button to Calculate and set its name property to btnCalculate. 5. Double click the btnCalculate to open the script window. 6. Enter the code as shown: How Does it Work? • In the 1st line declare the “i” variable as an integer. • In the 2nd line declare the “sum” variable as an integer. • In the 3rd line set the value of “sum” to 0. • In the 4th line For loop is defined that i=1 to 50 means it will run 50 times and increment 1 in the value of sum. • In the 5th line, while the loop runs every time it will add the value of “i” in the sum variable. Do...Next Loop Do...Next loop is used when we don’t know exactly how many times this loop will run. Do loop will run until a condition is met or while a condition is true. Follow the steps to create a program to add all integers starting from 1 until the sum is 500 or greater. 1. Create a new form. Drag a button control and a ListBox control from the toolbox panel and place it on the form. 2. Set the text property of the button to Calculate and its name property to btnCalculate. 3. Set the name property of the listBox to lstResults. 4. Double click the Calculate button to open the script window. 5. Enter the code shown: 91 The City School 2023-2024
How Does it Work? • The Do…Loop structure does not increment any counter variable automatically, so we have included the instruction i = i + 1 to increment it by one inside the loop. • With the instruction lstResults.Items.Add(i & vbTab & sum), we add one line in each loop to the ListBox, containing the current counter value and the current sum. • The & operator is used to concatenate the different values into a single line and the vbTab is a predefined constant of Visual Basic representing a tab space. • The loop here runs for as long as the value of the sum is smaller than 500. 4.11. Event Handling Mouse Event Events are basically a user action like key press, clicks, mouse movements, etc., or some occurrence like system generated notifications. Applications need to respond to events when they occur. Mouse events occur with mouse movements in forms and controls. Following are the various mouse events: Event Description MouseDown It occurs when a mouse button is pressed MouseEnter it occurs when the mouse pointer enters the control element MouseHover it occurs when the mouse pointer hovers over the control element MouseLeave it occurs when the mouse pointer leaves the control element MouseMove it occurs when the mouse pointer moves over the control element MouseUp it occurs when the mouse pointer is over the control element and the mouse button is released 92 The City School 2023-2024
Developing Applications Follow the steps to create a program in which we will detect the MouseHover event in VS. In the following example, we are going to display a pop-up window containing a message, whenever the mouse hovers on the button inside our program’s form. 1. Create a new form only with one button. 2. Double click on the button to open the script menu and then open the general tab on the top of the current script window as shown in the example. 3. Select (Form1 Events). 4. Then open the declaration window right next to it to select the MouseEvent by scrolling down which is MouseHover in this case. After selecting the MouseHover option from the declaration window, additional code will automatically be added. In that part, we will add a predefined feature MsgBox(). 5. Next, we will declare a string value to display in parenthesis of this MsgBox(“this popup window appears whenever the mouse hovers on this button”) 6. Execute the program by pressing the debugging button to test the program. 4.12.Functions and Subroutines Function is a type of procedure that returns a value that is passed on to the main procedure to finish execution. A function is similar to a subprocedure but there is one major difference, a function returns a value whilst a subprocedure does not. In Visual Basic 2010, there are two types of functions: • the built-in functions • user-defined functions-functions created by programmers Creating user-defined functions To create a user-defined function in Visual Basic 2010, you can use the following syntaxes: 93 The City School 2023-2024
Public: The keyword public indicates that the function applies to the whole project. Private: The keyword private indicates that the function only applies to a certain module or procedure. Arguments: The argument is a parameter that can pass a value back to the function. There is no limit to the number of arguments that can be added. Private Function functionName (Argument As dataType....) As dataType To demonstrate how user-defined functions are created, let create a BMI calculator that can caluclate the body-mass index of a person based on his or her body weight in Kgs and heign in meters. BMI can be calculated using the formula: weight/(height)2, where height is measured in meters and weight in Kgs. Following are the range of BMI values to determine weight status: • underweight: <18.5 • normal weight: 18.5-24.9 • overweight: 25-29.9 • obesity: >30 1. Create a new form. Drag four labels, two textboxes and one button from the toolbox. 2. Set the name property of the labels as: Height, Weight BMI and Result respectively. Set the name property of Result label as lblBMIResult. 3. Set the text property of button to Calculate BMI and name property of the button to btnBMI. 4. Double click on the button to open the script window. 5. Enter the following code to create a function. Public Function functionName (Argument As dataType....) As dataType 94 The City School 2023-2024
Developing Applications 4.13. Modules Visual Basic application source code is structured into module files with a .vb suffix. By default, Visual Studio creates a separate module file for each form in an application containing the code to construct the form. For example, the code to create a form called Form1 will be placed in a module file named Form1.Designer.vb. Similarly, any code that has been defined by the developer to handle events from controls in the form will be placed by Visual Studio into a module file called Form1.vb. Using modules in VB are recommended while creating a complex application as they save space in your code and also assist to reuse of code like functions. Checkpoint Decision making statements, give different results for different inputs. Loops allow a sequence of instructions to be repeated until a certain condition is reached. Follow the steps below to create using modules: 1. Create a form with one text box and a button and change the text to “Code from Module”. 2. Right-click on the project from the solution explorer window and go to Add and then go to Module and click 3. In the next window Module will be automatically selected give the name to Module or just click on Add. 4. After that, you will see the Module1.vb will start appearing in the solution explorer window and the script window of the module will also open. 5. In between the Module and End Module lines, we will add our Subroutine. 6. Using an element from another form in a module requires a declaration with the name of the form. In this case Form1.TextBox1 is the name of the element from the other form and its text will appear in the vbinformation box with the title defined as a string. 95 The City School 2023-2024
1. Now go back to the form and double click on the button to open the script window 2. It is highly recommended to use the comments while using code from a module to remember its functionality. Commenting is easy in VB using a ‘ single quote. 3. To use the Subroutine/Function in this form we will simply write its name in this case Pakistan(). 4. The green line above the sub with a single ‘ quote is the comment. 4.14. Program Debugging and Error Handling Error handling is an essential procedure in Visual Basic 2010 programming that helps make a program error-free. The user does not have to face all sorts of problems such as program crashes or system hangs. Errors often occur due to incorrect input from the user. For example, the user might make the mistake of attempting to enter text (string) to a box that is designed to handle only numeric values such as the weight of a person, the computer will not be able to perform the arithmetic calculation for text, therefore, will create an error. These errors are known as synchronous errors. To demonstrate error handling, we will deal with the error of entering non-numeric data into text boxes that are supposed to hold numeric values. The program_label here is error_hanldler. When the user enters non-numeric values into the textbox, the error message will display the text “One of the entries is not a number! Try again!” If no error occurs, it will display the correct answer. Checkpoint Function is a type of procedure that returns a value that is passed on to the main procedure to finish execution. A module is used to organise code and wrap up variables, properties, events, and procedures of similar use. 96 The City School 2023-2024
Developing Applications 1. Create a new form. Drag five labels, two text boxes, and a button and place it on to the form. 2. Set the text property of the 1st label to First Number and its name property to firstNumber. 3. Change the text of the 2nd label to Second Number and its name property to secondNumber. 4. Set the text property of the 3rd label to Division. 5. Set the text property of the 4th label to Result and change its name to lblAnswer. 6. Clear the text of the 5th label to hide it while the program is running and name it lbl_errorMsg. 7. Set the text property of the button control to Calculate and also change its name property to CmdCalculate. 8. Double click on the button to open script window and type this code. 97 The City School 2023-2024
1. The user interface is the graphical layout of an application. 2. A good user interface is clear, consistent, simple, direct, responsive and attractive. 3. Public variables are variables that are accessible to the whole program. 4. Private variables are variables that are accessible only to a certain part of the program or code. 5. Decision making statements allow to specify one or more conditions to be executed if the condition is determined to be true. 6. Logical operators return boolean result. 7. Loop is a sequence of instructions that is repeated until a certain condition is reached. 8. Events are a user action like key press, clicks, mouse movements, etc 9. Function is a type of procedure that returns a value that is passed on to the main procedure to finish execution. 10. Error handling is an essential procedure that helps make a program errorfree. Let’s Review My Notes! 98 The City School 2023-2024
Robot Profile Sophia is the world’s first robot citizen and the first robot Innovation Ambassador for the United Nations Development Programme. Sophia was created to help people in real uses like medicine and education, and to serve AI research. Her very existence provokes public discussion regarding AI ethics and the role humans play in society, especially when human-like robots become ubiquitous. Appearance • Human-sized appearance • Most realistic human-like expressive face • Patented artificial skin • Customized skin tone, facial design, language and arm colors available Sophia 2020 Key Features Expression • Integrated set of human-like emotional expressions • Sentence and context understanding with cloud connection • Mouth, face and whole body motion synchronized with speech output Sensors • Face detection and body tracking • Can be programmed for wide range of physical interaction tasks Motion • 74 degrees of freedom • Articulated fingers, arms and shoulders • Three different rolling base options including self- navigating • 600 gr. payload for each hand
Student Learning Outcomes ISTE Student Standard Coverage 1. Understand what single board computers is 2. Understand what Raspberry Pi, Raspbian OS and its components 3. Understand the components of Raspberry Pi 4. Understand the basics of Python Programming Language 5. Create an electric circuit using jumper wires, breadboard, resistor & LED 6. Understand what SONAR and Servo motor 7. Create and code a program for interacting with SONAR 8. Create and code a program for interacting with Servo Motor 9. Build a smart robotic car After going through this chapter, students will be able to: Empowered Learner Creative Communicator Global Collaborator Computational Thinker 1a 1d 5a 5d 6d 7c Programming Robots & Single Board Computers