Is there a way to method chain .push and .shift array methods?

Question

Here's my code:

var myArr = [1,2,3,4,5];
function queue(arr, item) {
  return arr.push(item).shift();
}

I'm attempting to create a function queue which takes an "array" and an "item" as arguments. I need to

1. Add the item onto the end of the array
2. Remove the first element of the array
3. Return the element that was removed.

My code is not working. Can you help me figure this out?

Answer 1

Just don't chain the method calls:

function queue(arr, item) {
  arr.push(item);
  return arr.shift();
}

Or, if you want a single statement,

function queue(arr, item) {
  return arr.push(item), arr.shift();
}

Alternatively, if you are mad enough, you could subclass Array and add a chainable push:

class MyArray extends Array {
  chainablePush(item) {
    this.push(item);
    return this;
  }
}
var myArr = new MyArray(1,2,3);
myArr.chainablePush(4).shift(); // 1
myArr; // MyArray [2,3,4];

Answer 2

because arr.push returns the length of the array, you can't chain the shift like that

simply do this

function queue(arr, item) {
  arr.push(item);
  return arr.shift();
}