Queue/Usage: Difference between revisions

=={{header|REXX}}==

The REXX language was developed under IBM VM/CMS operating system, and CMS had a stack mechanism built-into the

<br>operating system, so REXX utilized that resource.

<br>The entries in the stack may be anything, including "nulls".

<lang rexx>/*REXX program demonstrates three queue operations: push, pop, queued. */

say '══════════════════════════════════Pushing five values to the stack.'

do j=1 for 4 /*loop to PUSH four values. */

say '══════════════════════════════════The stack is now empty.'

exit

/*─────────────────────────────────────subroutines/functions/operators. */

push: queue arg(1); return /*REXX QUEUE is FIFO. */

pop: procedure; pull x; return x /*REXX PULL removes a stack item*/

empty: return queued()==0 /*returns the status of the stack*/</lang>

══════════════════════════════════Pushing five values to the stack.

pushed value: 10