JSFiddle - React, Tailwind, and code Playground

by Valentin Radulescu

HTML

<div class="out"></div>

CSS

.out{
    color: #fff;
    font-family: monospace;
    background-color: #222;
    padding: 20px;
    border-radius: 10px;
}

JavaScript

var arr = [1,2,3,4];
function duplicate(arr){
    var len = arr.length;
    for(var i=0; i<len; i++){
        arr.push(arr[i]);
    }
    return arr;
}
$('<p/>').text('arr: ' + arr).appendTo('.out')
$('<p/>').text('duplicate(arr): '+ duplicate(arr)).appendTo('.out');