How to implement Array.prototype.unshift? JavaScript Interview Question | Problem Solving | JavaScript Polyfills

In this question, the candidate needs to implement a function customUnshift that mimics the behaviour of Array.prototype.unshift method.

More about Array.prototype.unshift

The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.

Examples

const array = [1, 2, 3];

array.unshift(4, 5);

// prints [4,5,1,2,3]
console.print(array);

Syntax

unshift(element0)
unshift(element0, element1)
unshift(element0, element1, /* … ,*/ elementN)

Parameters

• elementN

The elements to add to the front of the arr.

Return value

The new length property of the object upon which the method was called.

Submission

Start the timer, complete your solution, and test it against the testcases provided by the platform. Ideally, you should finish this question within 30 mins. Share your solution with us -- https://twitter.com/devtoolstech