Sometimes you may need to test multiple "mutually exclusive" conditions -- a series of conditions only one of which will be true and the If...ElseIf construct tests for as many such conditions as need to be tested.

The set of statements1 is executed,If condition1 is evaluated as True; if condition1 is evaluated as False, then condition2 is evaluated and if this expression is evaluated as True, then the set of statements2 is executed; if the expression is evaluated as False, then the condition3 is evaluated, and so forth for as many tests as are coded. In case none of the previous tests is evaluated as True,the final, optional, Else condition is provided . It is "default" condition and The point of the structure is that only one of the parallel tests can be evaluated as True, and only one set of statements is executed.

The example below uses a set of If...ElseIf statements to check whether an entered character is in the first, middle, or last third of the alphabet.

For testing with the string operator,the character entered is converted to upper case Like against a set of characters represent the first, middle, and last thirds of the alphabet and a set of If...ElseIf statements is used because only one of the parallel tests will be true, and in case a non-alphabetic character is entered,an Else condition is provided.

Of course, a standard If...Else construct could be used for these tests. However, their construction is more difficult to write and to visualize, and each If statement must be paired with an End If statement.