JSFiddle - React, Tailwind, and code Playground

JS Sanity Check

by austegard

JavaScript

var arr = [{id: 1, name:"bob"}];

var prop = arr[0].name; //copy by value
var obj = arr[0]; //copy by reference

var b = $("body");
b.append("prop = " + prop + "<br>");
b.append("obj.name = " + obj.name + "<br>");
b.append("Updating value -> barb<br>");
arr[0].name = "barb";
b.append("prop = " + prop + "<br>");
b.append("obj.name = " + obj.name + "<br>");

b.append("Copying Array<br>");

var arr2 = arr; //also copy by reference

b.append("obj.name = " + obj.name + "<br>");
b.append("arr2[0].name = " + arr2[0].name + "<br>");
b.append("Updating value in original array -> beth<br>");
arr[0].name = "beth";
b.append("obj.name = " + obj.name + "<br>");
b.append("arr2[0].name = " + arr2[0].name + "<br>");