typedArray.keys

arr.keys()

var arr = new Uint8Array([10, 20, 30, 40, 50]
var eArray = arr.keys(
// your browser must support for..of loop
// and let-scoped variables in for loops
for (let n of eArray) {
  console.log(n
}

var arr = new Uint8Array([10, 20, 30, 40, 50]
var eArr = arr.keys(
console.log(eArr.next().value // 0
console.log(eArr.next().value // 1
console.log(eArr.next().value // 2
console.log(eArr.next().value // 3
console.log(eArr.next().value // 4