Public Questions for tag [object]

What's the best way of checking if an object property in JavaScript is undefined?

What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but that's non-standard and only supported by Firefox.I've done things like obj = JSON.parse(J

Say I create an object as follows:let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*", }; How should I remove the property regex to end up with new myObject as