Each slice javascript

each_slice.js

// without callback
Array.prototype.eachSlice = function (size){
  this.arr = []
  for (var i = 0, l = this.length; i < l; i += size){
    this.arr.push(this.slice(i, i + size))
  }
  return this.arr
};

[1, 2, 3, 4, 5, 6].eachSlice(2)

// output
/* [ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ] ] */

// with callback
Array.prototype.eachSlice = function (size, callback){
  for (var i = 0, l = this.length; i < l; i += size){
    callback.call(this, this.slice(i, i + size))
  }
};

[1, 2, 3, 4, 5, 6].eachSlice(2, function(slice) { 
  console.log(slice)
})

// output
/*
  [ 1, 2 ]
  [ 3, 4 ]
  [ 5, 6 ]
*/