Array.prototype.shift() - JavaScript

Array.prototype.entries()
Array.prototype.find()
Array.prototype.flat()
Array.prototype.indexOf()
Array.prototype.map()
Array.prototype.reduceRight()
Array.prototype.some()
Array.prototype.toReversed()
Array.prototype.unshift()
Array: length
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Function: displayName Non-standard
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Function.prototype.caller Non-standard Deprecated

Instance methods

Object.prototype.__defineGetter__() Deprecated
Object.prototype.__defineSetter__() Deprecated
Object.prototype.__lookupGetter__() Deprecated
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Array instances removes the first element from an array and returns that removed element. This method changes the length of the array.

Try it

const array1 = [1, 2, 3];

const firstElement = array1.shift();

console.log(array1);
/ Expected output: Array [2, 3]

console.log(firstElement);
/ Expected output: 1

Syntax

shift()

Return value

The removed element from the array; undefined is returned.

The pop() method has similar behavior to shift(), but applied to the last element in an array.

The shift() method is a arr.slice(1) instead.

The shift() method is generic. It only expects the this value to have a length property and integer-keyed properties. Although strings are also array-like, this method is not suitable to be applied on them, as strings are immutable.

Examples

Removing an element from an array

The following code displays the myFish array before and after removing its first element. It also displays the removed element:

const myFish = ["angel", "clown", "mandarin", "surgeon"];

console.log("myFish before:", myFish);
/ myFish before: ['angel', 'clown', 'mandarin', 'surgeon']

const shifted = myFish.shift();

console.log("myFish after:", myFish);
/ myFish after: ['clown', 'mandarin', 'surgeon']

console.log("Removed this element:", shifted);
/ Removed this element: angel

Using shift() method in while loop

The shift() method is often used in condition inside while loop. In the following example every iteration will remove the next element from an array, until it is empty:

const names = ["Andrew", "Tyrone", "Paul", "Maria", "Gayatri"];

while (typeof (i = names.shift()) !== "undefined") {
  console.log(i);
}
/ Andrew, Tyrone, Paul, Maria, Gayatri

Calling shift() on non-array objects

The shift() method reads the length property of this. If the deleted, and the length property is decremented by one.

const arrayLike = {
  length: 3,
  unrelated: "foo",
  2: 4,
};
console.log(Array.prototype.shift.call(arrayLike));
/ undefined, because it is an empty slot
console.log(arrayLike);
/ { '1': 4, length: 2, unrelated: 'foo' }

const plainObj = {};
/ There's no length property, so the length is 0
Array.prototype.shift.call(plainObj);
console.log(plainObj);
/ { length: 0 }

Specifications

Specification
ECMAScript® 2026 Language Specification # sec-array.prototype.shift