Typescript swap array Items

Question

how to swap two elements using typescript

elements:elements[] =[];
elements.push(item1);
elements.push(item2);
elements.push(item3);
elements.push(item4);


elements[0] is item1 
elements[3] is item4

How can i interchange these items in typescript. i know Javascript way, like this:

*javascript example using temp variable *

var tmp = elements[0];
elements[0] = elements[3];
elements[3] = tmp;

but there is any api doing same thing in typescript like array.swap()

Answer 1

Why not use destructuring and an array.

[elements[0], elements[3]] = [elements[3], elements[0]];

Answer 2

There's no builtin functionality for it, but you can easily add it:

interface Array<T> {
    swap(a: number, b: number): void;
}

Array.prototype.swap = function (a: number, b: number) {
    if (a < 0 || a >= this.length || b < 0 || b >= this.length) {
        return
    }

    const temp = this[a];
    this[a] = this[b];
    this[b] = temp;
}

(code in playground)

If you are using modules then you'll need to do this to augment the Array interface:

declare global {
    interface Array<T> {
        swap(a: number, b: number): void;
    }
}

Answer 3

swapArray(Array:any,Swap1:number,Swap2:number) : any
{
    var temp = Array[Swap1];
    Array[Swap1] = Array[Swap2]
    Array[Swap2] = temp
    return Array;
}