A-M baby

Task/Flow-control-structures/REXX/flow-control-structures-1.rexx

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+exit
+
+exit  expression

Task/Flow-control-structures/REXX/flow-control-structures-2.rexx

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+return
+
+return  expression

Task/Flow-control-structures/REXX/flow-control-structures-3.rexx

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+signal on error
+signal on failure
+signal on halt
+signal on lostdigits
+signal on notready
+signal on novalue
+signal on syntax
+
+signal off error
+signal off failure
+signal off halt
+signal off lostdigits
+signal off notready
+signal off novalue
+signal off syntax
+ ∙
+ ∙
+ ∙
+signal on novalue
+ ∙
+ ∙
+x=oopsay+1
+ ∙
+ ∙
+ ∙
+novalue: say
+say '*** error! ***'
+say
+say 'undefined REXX variable' condition("D")
+say
+say 'in line' sigl
+say
+say 'REXX source statement is:'
+say sourceline(sigl)
+say
+exit 13
+ ∙
+ ∙
+ ∙

Task/Flow-control-structures/REXX/flow-control-structures-4.rexx

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+  do j=1  to 10
+  say 'j=' j
+  if j>5  then leave
+  say 'negative j=' -j
+  end
+say 'end of the DO loop for j.'
+ ∙
+ ∙
+ ∙
+ouch=60
+sum=0
+
+  do k=0  to 100  by 3
+  say 'k=' k
+
+     do m=1  to k
+     if m=ouch  then leave k
+     sum=sum+m
+     end
+
+  end
+say 'sum=' sum

Task/Flow-control-structures/REXX/flow-control-structures-5.rexx

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+sum=0
+
+  do j=1  to 1000
+  if j//3==0 | j//7==0  then iterate
+  sum=sum+j
+  end
+
+           /*shows sum of 1k numbers except those divisible by 3 or 7.*/
+say 'sum='sum
+ ∙
+ ∙
+ ∙
+numeric digits 5000
+prod=0
+
+  do k=1  to 2000
+
+     do m=1  to k
+     if m>99  then iterate k
+     prod=prod*m
+     end
+
+  end
+say 'prod=' prod

Task/Flow-control-structures/REXX/flow-control-structures-6.rexx

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+numeric digits 1000               /*prepare for some gihugeic numbers.*/
+ ∙
+ ∙
+ ∙
+n=4
+call factorial n
+say n'!=' result
+exit
+
+
+factorial: parse arg x
+!=1
+
+  do j=2  to x
+  !=!*j
+  end
+
+return !

Task/Flow-control-structures/REXX/flow-control-structures-7.rexx

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+ ∙
+ ∙
+ ∙
+prod=1
+a=7               /*or somesuch.*/
+b=3               /*  likewise. */
+
+op='**'           /*or whatever.*/
+ ∙
+ ∙
+ ∙
+  select
+  when op=='+'         then  r=a+b           /*add.                   */
+  when op=='-'         then  r=a-b           /*subtract.              */
+  when op=='*'         then do; r=a*b; prod=prod*r; end    /*multiply.*/
+  when op=='*'         then  r=a*b           /*multiply.              */
+  when op=='/'  & b\=0 then  r=a/b           /*divide.                */
+  when op=='%'  & b\=0 then  r=a/b           /*interger divide.       */
+  when op=='//' & b\=0 then  r=a/b           /*modulus (remainder).   */
+  when op=='||'        then  r=a||b          /*concatenation.         */
+  when op=='caw'       then  r=xyz(a,b)      /*call the XYZ subroutine*/
+  otherwise                  r='[n/a]'       /*signify not applicable.*/
+  end
+
+say 'result for' a op b "=" r