Does it mutate 😱

Array.prototype.push

Mutates

Description

The push() method of Array instances adds the specified elements to the end of an array and returns the new length of the array.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push

Example

const animals = ['pigs', 'goats', 'sheep'];

const count = animals.push('cows');
console.log(count);
// Expected output: 4
console.log(animals);
// Expected output: Array ["pigs", "goats", "sheep", "cows"]

animals.push('chickens', 'cats', 'dogs');
console.log(animals);
// Expected output: Array ["pigs", "goats", "sheep", "cows", "chickens", "cats", "dogs"]