JSFiddle - React, Tailwind, and code Playground

by ponyspy

JavaScript

var move = function (arr, old_index, new_index) {
    while (old_index < 0) {
        old_index += arr.length;
    }
    while (new_index < 0) {
        new_index += arr.length;
    }
    if (new_index >= arr.length) {
        var k = new_index - arr.length;
        while ((k--) + 1) {
            arr.push(undefined);
        }
    }
    arr.splice(new_index, 0, arr.splice(old_index, 1)[0]);
    return arr;
};

var in_arr = [1,2,3]

alert(move(in_arr, 0, 1))