Fortran - if-else if-else Construct
An if statement construct can have one or more optional else-if constructs. When the if condition fails, the immediately followed else-if is executed. When the else-if also fails, its successor else-if statement (if any) is executed, and so on.
The optional else is placed at the end and it is executed when none of the above conditions hold true.
All else statements (else-if and else) are optional.
else-if can be used one or more times.
else must always be placed at the end of construct and should appear only once.
The syntax of an if...else if...else statement is −
[name:] if (logical expression 1) then ! block 1 else if (logical expression 2) then ! block 2 else if (logical expression 3) then ! block 3 else ! block 4 end if [name]
program ifElseIfElseProg implicit none ! local variable declaration integer :: a = 100 ! check the logical condition using if statement if( a == 10 ) then ! if condition is true then print the following print*, "Value of a is 10" else if( a == 20 ) then ! if else if condition is true print*, "Value of a is 20" else if( a == 30 ) then ! if else if condition is true print*, "Value of a is 30" else ! if none of the conditions is true print*, "None of the values is matching" end if print*, "exact value of a is ", a end program ifElseIfElseProg
When the above code is compiled and executed, it produces the following result −
None of the values is matching exact value of a is 100