Function map

src/utils/collections.js:91–99

(input, fn)

}

function map(input, fn) {
  let length = input.length,
    result = new Array(length),
    i
  for (i = 0; i < length; i++) {
    result[i] = fn(input[i])
  }
  return result
}

function forEach(arr, fn) {
  let length = arr.length,