CBSE Class 8 Computer Science Chapter 12

CBSE Class VIII Computer Science Chapter 12 – More on Visual Basic

Visual Basic is a software tool that contains various built in tools and components to design a GUI application. The controls available in the Toolbox are commonly used to design a Visual Basic application. Various images and shapes can be added to a form to design an attractive GUI application using Picture Box Control, Shape Control and Image Control. In Visual Basic, variables are declared using the Dim statement to store data temporarily.  

Operators are symbols that are used to perform calculations on operands while executing an application. The three types of operators in VB are arithmetic operators, relational operators and logical operators. Arithmetic operators are used to perform arithmetic calculations such as addition, subtraction etc. Relational operators are used to compare two values and accordingly return either True or False as a result. Logical operators are used to combine more than one logical condition while applying logic in a program.  

Control statements control the flow of program execution either by repeating or skipping the set of statements based on the result of the test condition. Control statements used in VB are sequential statement, selection statement and looping statement. In a sequential statement, statements are executed one by one till the end of a program. In a selection statement, statements execute according to the result of the test condition. Looping statement executes repeatedly till the result of the text condition remains true.