Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.81 UNTIL Statement
UNTIL (e)
where:
e
is a logical expression or integer arithmetic expression, in which case the result of the integer
expression is compared for inequality to the integer value 0.
The UNTIL statement is used in conjunction with the structured LOOP or block WHILE statement. The
LOOP or block WHILE statement marks the beginning of a sequence of statements which are to be repeated.
The UNTIL statement marks the end of the loop. The LOOP-block or WHILE-block is executed until
control is transferred out of the block or the logical expression of the UNTIL statement has a true value.
Example:
Example:
X = 1.0
LOOP
PRINT *, X, SQRT( X )
X = X + 1.0
UNTIL( X .GT. 10.0 )
I = 1
WHILE( I .LT. 100 )DO
J = 4 * I * I
K = 3 * I
PRINT *, ’4x**2 + 3x + 6 = ’, J + K + 6
I = I + 1
UNTIL( ( J + K + 6 ) .GT. 100 )
For more information, see the chapter entitled "Program Structure Control Statements" on page 193.
UNTIL Statement 143