let text = "";
function add()
{
var node = Node.prototype;
nodeList = NodeList.prototype;
const xxx = ["q", "w", "e", "r", "t"];
xxx.forEach(change);
console.log(xxx);
console.log(text);
/*notice the array does not change but text does*/
}
function change(item, index) {
text += item+index;
}