Open Watcom FORTRAN 77 Language Reference

Language Reference
9.13 QUIT
QUIT
[ : block-label]
The QUIT statement may be used to transfer control to the first executable statement following the terminal
statement of the block in which it is contained.
When transferring out of a loop, control is passed to the statement following the END DO, END WHILE,
END LOOP or UNTIL statement.
When transferring out of a GUESS block, control is passed to the statement after the next ADMIT or END
GUESS statement.
When transferring out of an IF-block or SELECT-block, control is passed to the statement after the
corresponding END IF or END SELECT statement.
When transferring out of a REMOTE-block, control passes to the statement following the EXECUTE
statement that invoked the REMOTE-block.
If no block label is specified in the QUIT statement, control is transferred from the immediately enclosing
structure. If several structures or DO-loops are nested, it is possible to exit from any one of them by
specifying the block label of the corresponding block structure.
The QUIT statement is most commonly used as the statement in a logical IF or AT END statement but
may also be used to cause an unconditional transfer of control. (The AT END statement is described in a
subsequent section).
Examples of the QUIT statement with and without a block label follow.
Example:
CHARACTER CH
READ *, CH
GUESS
IF( CH .LT. ’a’ )QUIT
IF( CH .GT. ’z’ )QUIT
PRINT *, ’Lower case letter’
ADMIT
IF( CH .LT. ’A’ )QUIT
IF( CH .GT. ’Z’ )QUIT
PRINT *, ’Upper case letter’
ADMIT
IF( CH .LT. ’0’ )QUIT
IF( CH .GT. ’9’ )QUIT
PRINT *, ’Digit’
ADMIT
PRINT *, ’Special character’
END GUESS
END
The above statements read and print values until an end of file occurs. At that point control is passed to the
QUIT statement, as specified by the AT END statement. The QUIT statement causes control to continue
with the statement after the END LOOP statement.
208 QUIT