Unshift

The unshift method adds new elements sequentially to the start, or front of the array. It modifies the original array and returns the new length of the array. For example.

let array = [0, 5, 10];
array.unshift(-5);  // 4

// RESULT: array = [-5 , 0, 5, 10];

The unshift method takes one or more arguments, which represent the elements to be added to the beginning of the array. It adds the elements in the order they are provided, so the first element will be the first element of the array.

Here is an example of using unshift to add multiple elements to an array:

const numbers = [1, 2, 3];
const newLength = numbers.unshift(-1, 0);
console.log(numbers); // [-1, 0, 1, 2, 3]
console.log(newLength); // 5