Open Watcom FORTRAN 77 Language Reference

Language Reference
2.24 ELSE Statement
ELSE
The ELSE statement is used in conjunction with the IF or ELSE IF statement. The range of the ELSE
block is terminated by a matching END IF statement.
Example:
IF( A .LT. B )THEN
PRINT *, ’A is less than B’
ELSE
PRINT *, ’A is greater than or equal to B’
END IF
Transfer of control into the range of an ELSE block is illegal. It is interesting to note that the ELSE
statement may be identified by a statement label but it must not be referenced by any statement!
Example:
* Illegal branch to a labelled ELSE statement.
IF( A .LT. B )THEN
PRINT *, ’A is less than B’
100 ELSE
PRINT *, ’A is greater than or equal to B’
GO TO 100
END IF
The above is an example of an illegal way to construct an infinitely repeating loop. The following is the
correct way to do this.
Example:
IF( A .LT. B )THEN
PRINT *, ’A is less than B’
ELSE
100 PRINT *, ’A is greater than or equal to B’
GO TO 100
END IF
For more information, see the chapter entitled "Program Structure Control Statements" on page 193.
54 ELSE Statement