javascript - Extract "N" Values from an Array -

objective

"chunky monkey" problem: create new, multi-dimensional array given array ('arr') , number ('size'). new, multi-dimensional array should create array lengths equal 'size' variable.

example #1

chunk(['a', 'b', 'c', 'd'], 2); var answer = []; function chunk(arr,size){ //do };  return answer 

expected answer #1

answer = [['a','b'],['c','d']]; 

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example #2

below example when there odd number of elements/sizes - in situation this, expected result have "remainder" group.

chunk(['a', 'b', 'c', 'd'], 3);     var answer = [];     function chunk(arr,size){     //do     };      return answer 

expected answer #2

answer = [['a','b','c'],['d']]; 

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my pseudo-code / approach

var final = []; function chunk(arr, size) {   //extract number of elements 'arr' = 'size'    var extract = function{     //help! [insert logic]   };    //add extracted elements 'group' array   var group = [extract];    //push 'group' 'final' array multidimensional array   final.push(group);    //return final'   return final; }  chunk(['a', 'b', 'c', 'd'], 2); 

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questions

1. i've been looking @ .foreach(), for(in) loops, .slice(), etc. no avail. of approaches result in cycling through array, not "pairing them".
2. am over-complicating things? there more direct approach pseudo-code/approach?

you can use recursive function:

function chunk(arr, size) {     if(!arr.length) return [];     return [arr.slice(0, size)].concat(chunk(arr.slice(size), size)); } 

or loop:

function chunk(arr, size) {     arr = arr.slice();     var ret = [];     while(arr.length) ret.push(arr.splice(0, size));     return ret; }