Data commit

Task/Create-a-two-dimensional-array-at-runtime/REXX/create-a-two-dimensional-array-at-runtime.rexx

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+/*REXX program  allocates/populates/displays  a two-dimensional array.  */
+call bloat                   /*the BLOAT procedure does all allocations.*/
+                             /*no more array named   @   at this point. */
+exit                         /*stick a fork in it, we're all done honey.*/
+/*─────────────────────────BLOAT subroutine─────────────────────────────*/
+bloat: procedure;  say       /*"PROCEDURE"  makes this a ··· procedure. */
+say 'Enter two positive integers (a 2-dimensional array will be created).'
+pull n m .                   /*elements are allocated as they're defined*/
+                             /*N and M should be verified at this point.*/
+@.=' · '                     /*Initial value for all  @  array elements,*/
+                             /*this ensures  every  element has a value.*/
+  do j    =1  for n          /*traipse through the first  dimension  [N]*/
+      do k=1  for m          /*   "       "     "  second     "      [M]*/
+      if random()//7==0  then @.j.k=j'~'k    /*populate every 7th random*/
+      end  /*k*/
+  end        /*j*/
+                             /* [↓]  display array to console:  row,col */
+  do r=1  for n;    _=       /*construct one row (or line) at a time.   */
+      do c=1  for m          /*construct row one column at a time.      */
+      _=_ right(@.r.c,4)     /*append a nice-aligned column to the line.*/
+      end   /*kk*/           /* [↑]   an nicely aligned line is built.  */
+  say _                      /*display one row at a time to the terminal*/
+  end         /*jj*/
+/*╔════════════════════════════════════════════════════════════════════╗
+  ║ When the  RETURN  is executed (from a PROCEDURE in this case), and ║
+  ║ array   @  is "de─allocated", that is, it's no longer defined, and ║
+  ║ the array's storage is now free for other REXX variables.   If the ║
+  ║ BLOAT   subroutine didn't have a   "PROCEDURE"   on that statement,║
+  ║ the array    @    would've been left intact.    The same effect is ║
+  ║ performed by a   DROP   statement   (an example is shown below).   ║
+  ╚════════════════════════════════════════════════════════════════════╝*/
+drop @.                      /*because of the  PROCEDURE  statement, the*/
+return                       /* [↑]    DROP   statement is superfluous. */