Decision making allows programmers to control the execution flow of a script or one of its sections. The execution is governed by one or more conditional statements.
Following is the general form of a typical decision making structure found in most of the programming languages:
VBA provides following types of decision making statements. Click the following links to check their details.
| Statement | Description | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| if statement |
An If statement consists of a boolean expression followed by one or more statements. If the condition is said to be True, the statements under If condition(s) are Executed. If the Condition is said to be False, the statements after the If loop are executed.
Syntax :
The syntax of an If statement in VBScript is:
If(boolean_expression) Then Statement 1 ..... ..... Statement n End If Flow Diagram Example
For Demo purpose, we will find the biggest between two numbers of an Excel with the help of a function.
Private Sub if_demo_Click() Dim x As Integer Dim y As Integer x = 234 y = 32 If x > y Then MsgBox "X is Greater than Y" End If End Sub
When the above code is executed, it produces the following result:
X is Greater than Y | ||||||||||||
| if..else statement |
An If statement consists of a boolean expression followed by one or more statements. If the condition is said to be True, the statements under If condition(s) are Executed. If the Condition is said to be False, the statements under Else Part would be executed.
Syntax :
The syntax of an If Else statement in VBScript is:
If(boolean_expression) Then Statement 1 ..... ..... Statement n Else Statement 1 ..... .... Statement n End If Flow Diagram Example
For Demo purpose, we will find the biggest between two numbers of an Excel with the help of a function.
Private Sub if_demo_Click() Dim x As Integer Dim y As Integer x = 234 y = 324 If x > y Then MsgBox "X is Greater than Y" Else Msgbox "Y is Greater than X" End If End Sub
When the above code is executed, it produces the following result:
Y is Greater than X | ||||||||||||
| if...elseif..else statement |
An If statement followed by one or more ElseIf Statements that consists of boolean expressions and then followed by a default else statement, which executes when all the condition becomes false.
Syntax :
The syntax of an If Elseif - Else statement in VBScript is:
If(boolean_expression) Then Statement 1 ..... ..... Statement n ElseIf (boolean_expression) Then Statement 1 ..... .... Statement n ElseIf (boolean_expression) Then Statement 1 ..... .... Statement n Else Statement 1 ..... .... Statement n End If Flow Diagram Example
For Demo purpose, we will find the biggest between two numbers of an Excel with the help of a function.
Private Sub if_demo_Click() Dim x As Integer Dim y As Integer x = 234 y = 234 If x > y Then MsgBox "X is Greater than Y" ElseIf y > x Then Msgbox "Y is Greater than X" Else Msgbox "X and Y are EQUAL" End If End Sub
When the above code is executed, it produces the following result:
X and Y are EQUAL | ||||||||||||
| nested if statements |
An If or ElseIf statement inside another If or ElseIf statement(s). The Inner If statements are executed based on the Outermost If statements. This enables VBScript to handle complex conditions with ease.
Syntax :
The syntax of an Nested Ifstatement in VBScript is:
If(boolean_expression) Then Statement 1 ..... ..... Statement n If(boolean_expression) Then Statement 1 ..... ..... Statement n ElseIf (boolean_expression) Then Statement 1 ..... .... Statement n Else Statement 1 ..... .... Statement n End If Else Statement 1 ..... .... Statement n End If Example
For Demo purpose, we will find the type of positive number with the help of a function.
Private Sub nested_if_demo_Click() Dim a As Integer a = 23 If a > 0 Then MsgBox "The Number is a POSITIVE Number" If a = 1 Then MsgBox "The Number is Neither Prime NOR Composite" ElseIf a = 2 Then MsgBox "The Number is the Only Even Prime Number" ElseIf a = 3 Then MsgBox "The Number is the Least Odd Prime Number" Else MsgBox "The Number is NOT 0,1,2 or 3" End If ElseIf a < 0 Then MsgBox "The Number is a NEGATIVE Number" Else MsgBox "The Number is ZERO" End If End Sub
When the above code is executed, it produces the following result:
The Number is a POSITIVE Number The Number is NOT 0,1,2 or 3 | ||||||||||||
| switch statement |
When a User want to execute a group of statements depending upon a value of an Expression, then Switch Case is used. Each value is called a Case, and the variable being switched ON based on each case. Case Else statement is executed if test expression doesn't match any of the Case specified by the user.
Case Else is an optional statement within Select Case, however, it is a good programming practice to always have a Case Else statement.
Syntax :
The syntax of a Switch statement in VBScript is:
Select Case expression Case expressionlist1 statement1 statement2 .... .... statement1n Case expressionlist2 statement1 statement2 .... .... Case expressionlistn statement1 statement2 .... .... Case Else elsestatement1 elsestatement2 .... .... End Select Example
For Demo purpose, we will find the type of integer with the help of a function.
Private Sub switch_demo_Click() Dim MyVar As Integer MyVar = 1 Select Case MyVar Case 1 MsgBox "The Number is the Least Composite Number" Case 2 MsgBox "The Number is the only Even Prime Number" Case 3 MsgBox "The Number is the Least Odd Prime Number" Case Else MsgBox "Unknown Number" End Select End Sub
When the above code is executed, it produces the following result:
The Number is the Least Composite Number |
