JSFiddle - React, Tailwind, and code Playground

JavaScript

var array_of_numbers = [5,4,3,2,1,0],
    swap = function(array,a,b){var tmp=array[a];array[a]=array[b];array[b]=tmp;};
swap(array_of_numbers,0,4);
// array_of_numbers now is [1,4,3,2,5,0]
alert( array_of_numbers.join(',') );