# Variable nr. of nested loops (playing with recursion)

**URL:** <https://discourse.processing.org/t/variable-nr-of-nested-loops-playing-with-recursion/23561>\
**Category:** Gallery\
**Created:** [August 30, 2020, 4:52am UTC](https://discourse.processing.org/t/variable-nr-of-nested-loops-playing-with-recursion/23561 "2020-08-30T04:52:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![raron](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/raron/32/13651_2.png) [@raron](https://discourse.processing.org/u/raron)\
**Post date:** [August 30, 2020, 4:52am UTC](https://discourse.processing.org/t/variable-nr-of-nested-loops-playing-with-recursion/23561/1 "2020-08-30T04:52:46Z")

</div>

So I’m not sure how useful this is (or if it even belongs in the “Gallery”). I feel I might have overcomplicated something. Maybe it’s a solution looking for a problem 😛

First a simple version, with a factorial nr. of iterations for the inner loop:

> **Click to (un) expand**
>
> ```auto
> /** Nested loops using recursion
> 
> Each nested loop successively one less iteration than the "parent" loop, until 1 iteration.
> Forwards nesting levels
> 
> 2020.08.30 raron
> */
> 
> int nested = 4;
> int loopCounter = 0; // Innermost loop counter. Bsically factorial(!)
> 
> void setup()
> {
> println("Test");
> println();
> variableLoops(0);
>   
> println("nr. of innermost loops: " + loopCounter);
> }
> 
> void draw()
> {
> exit();
> }
> 
> void variableLoops(int looper)
> {
> if(looper == nested)
> {
> // innermost loop stuff here
> loopCounter++;
> return;
> }
> for(int tab=0; tab<looper; tab++) print("\t");
> println("Level " + (looper) + " : "); 
> for(int i=0; i<nested-looper; i++)
> {
> for(int tab=0; tab<looper; tab++) print("\t");
> println(" Count: " + i);
> variableLoops(looper+1);
> }
> }
> 
> ```

And then a better version, with any number of iterations pr. nested loop:

> **Click to (un) expand**
>
> ```auto
> /** Nested loops using recursion
> 
> Any number of iterations in each nested loop.
> 
> 2020.08.30 raron
> */
> 
> int [] loopLimit = { 4, 2, 3 }; // loop array, counting from 0 to each element value-1
> int nestedLoops = loopLimit.length; // nr. of nested loops
> int [] loopIndex = new int[nestedLoops]; // index counter of each loop
> 
> void setup()
> {
> for(int i=0; i<nestedLoops; i++) loopIndex[i] = 0;
>   
> variableLoops(0, loopLimit, loopIndex);
>   
> println(" Last count:");
> println(loopIndex);
>   
> noLoop();
> }
> 
> void draw()
> {
> exit();
> }
> 
> void variableLoops(int nestedLoop, int[] loopLimit, int[] loopIndex )
> {
> if(nestedLoop == loopLimit.length)
> {
> // innermost loop stuff here
> return;
> }
> 
> for(int tab=0; tab<nestedLoop; tab++) print("\t");
> println("Level: " + nestedLoop);
> for(int i=0; i<loopLimit[nestedLoop]; i++)
> {
> loopIndex[nestedLoop] = i;
> for(int tab=0; tab<nestedLoop; tab++) print("\t");
> println(" Count: " + i);
> variableLoops(nestedLoop+1, loopLimit, loopIndex);
> }
> }
> 
> ```