Some Useful Properties:

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Some Useful Properties

• Name
• Caption

• Border style
• Visible
• Back Color
• Alignment
• Font

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Naming Objects

• Use the Property window to change the Name
  property of an object
• Good Programming habit is that each name begins
  with three letter prefix that identifies the type
  of control.

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Naming Objects
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Visual Basic Events

• Code is a set of statements that will be executed
  when you run a program.
• Write Code for each Event.
• Most Events are associated with Objects.
• The code for each event is called an Event
  Procedure.

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The steps for creating a VB program

• Create the Interface.
• Set Properties for the objects.
• Write the code that executes when event occur.

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An Event Procedure Walkthrough

• Create the interface.
• Set Properties.
• Double click on the object to open the Code
  window.
• Click on the Procedure box to find the event
• Write the code for that event.

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Example

• Private Sub cmdButton_Click( )
• txtBox.ForeColor vbRed
• txtBox.Font.Size 24
• txtBox.Text Hello
• End Sub

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Components of Visual BASIC Statements

• Variables
• Keywords (reserved words)
• Constants

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Variables

• A storage location in main memory whose value can
  change during program execution.
• These storage locations can be referred to by
  their names.
• Every variable has three properties a Name, a
  Value, and a Data Type.
• Types of variables Numeric and String

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Numeric Variables

• Used to store Numbers .
• The value is assigned either by the programmer or
  by calculation.

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Constant

• Similar to a variable, but can NOT change during
  the execution of a program.
• Types of Constants
• numeric constants
• string constants

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Valid Numeric Constants

• Integer Real number
• -2987 -1900.05
• 16 0.0185
• 5 10.56

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Numeric Constants in a Statement

• tax 0.02 (income - 500 dependence)
• sum 2 x 4.6 y

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String Constants

• A group of alphanumeric data consisting of any
  type of symbols.

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Arithmetic Operations Hierarchy of Operations

• Operator operation Basic expression
• Exponentiation A
  B
• Multiplication A
  B
• / Division
  A / B
• Addition
  A B
• - Subtraction
  A - B

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Examples

• Evaluate the following expressions
• x 3 6 - 12 / 3
• x 4 (8 / 4)
• y 12 6 / (3 (10 - 9))
• z 5 4 2
• m 6 / 3 3

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Keywords

• Words that have predefined meaning to Visual
  Basic .
• Can Not be used as variable names.
• Example Print
• Cls
• If
• While

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Visual Basic Print Statement

• Print Is a method used to display data on the
  screen or printer.
• Can be used to print value of variables.
• Can be used to print value of arithmetic
  expressions .

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Example of Print Statements

• Private Sub cmdCompute_Click()
• picResults.Print 3 - 2
• picResults.Print 3 2
• picResults.Print 3 / 2
• picResults.Print 3 2
• picResults.Print 2 (3 4)
• End Sub

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Example of Print Statement

• picOutput.Print speed
• picOutput.Print taxRate
• picOutput.Print Class average is total / 3

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Example

• x 15
• y 5
• picOutput.Print (x y) / 2, x / y

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Output

• 10 3