chunckArray.js

/**
 * Returns an array with arrays of the given size.
 *
 * @param myArray {Array} Array to split
 * @param chunkSize {Integer} Size of every group
 */
function chunkArray(myArray, chunk_size){
  var results = [];
  
  while (myArray.length) {
    results.push(myArray.splice(0, chunk_size));
  }
  
  return results;
}

// Split in group of 3 items
var result = chunkArray([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15], 10);
// Outputs : [ [1,2,3] , [4,5,6] ,[7,8] ]
console.log(result);