Open Watcom FORTRAN 77 Language Reference

Language Reference
2.84 WHILE Statement
WHILE (e) stmt
where:
e
stmt
is a logical expression.
is an executable statement. Only certain executable statements are allowed. See the section
entitled "Classifying Statements" on page 9 at the beginning of this chapter for a list of allowed
statements.
This form of the WHILE statement allows an executable statement to be repeatedly executed until the
logical expression e is false.
Example:
I = 0
WHILE( I .LE. 100 ) CALL PRTSQR( I )
END
SUBROUTINE PRTSQR( J )
PRINT *, J, J**2
J = J + 1
END
In the above example, the subroutine PRTSQR is called again and again until the value of I has been
incremented beyond 100. Note that the subroutine increments its argument thereby guaranteeing that the
program will eventually stop execution.
For more information, see the chapter entitled "Program Structure Control Statements" on page 193 Control
Statements".
146 WHILE Statement