The If statement in VBA (Visual Basic for Applications) is essential for executing actions based on specific conditions defined by the user. This guide will walk you through the basic syntax and provide an example program to determine if a number entered by the user is positive or negative.
Syntax of the If Statement
This is the syntax of the If statement:
IF condition1 THEN
'What will the happen if the condition is met
ELSE
'What will the happen if the condition is not met
END IF
Explanation: The user defines the condition after the if statement to check whether it’s true or false. If the condition is true than the user in the next line defines what the code will do. However if the condition are not met then the user uses the else statement after which he/she defines what will happen if the condition are not met.
Our program will take an input from the user and tell whether it’s a positive number or a negative number.
Example Program: Checking Positive or Negative Number
Click on Developer tab and select View Code.
A new window (Visual Basic Editor) will open which would have a dialog box in the center.
Write the following line of code in the dialog box.
Sub Find_Negative()
On Error GoTo catch_error
Dim number As Integer
number = InputBox("Enter the number: ")
If number < 0 Then
MsgBox "Entered number is negative!"
Else
MsgBox "Entered number is positive!"
End If
Exit Sub
catch_error:
MsgBox "Oops, Some Error Occurred"
End Sub
After writing the code close the window by clicking on the cross(x) icon on the upper right side of the screen.
Explanation of the Code
In this code, we are first taking the input from the user (the input must be a number).we are checking whether the modulus (Mod) of that number with 2 is zero or not. If its zero than this means that the number is divisible by 2 and thus we display a message box saying the number is positive. If its modulus with 2 is not zero than that number is not perfectly divisible by 2.
Hence we display a message box saying that the number is negative. However if the user instead of entering a number enters a letter or a special character (like @) than we display a message box saying that an error has occurred.
This is the result if the user has entered a positive number.
This is the result if the user has entered a negative number.
This is the result if the user has entered a special character or a letter.
That’s it; you have now successfully used the If statement.
This basic example demonstrates how to check if a number is positive or negative, handle user input, and manage errors effectively.
