chunkArray.js

function chunkArray(arr, size) {
// creates a matrix of N elements from a single array

  var resultArray = [];
  
  for (var i = 0; i < arr.length; i += size) {
      resultArray.push(arr.slice(i, i + size));
  }
  
  return (resultArray);
      
}

chunkArray(["a", "b", "c", "d", "e"], 2);