Am I missing something for Javascript?

Hello, I have a small issue which apparently extends beyond just unity. I can’t seem to use object.create(), object.setprototypeof() or any function that is in this list:

Am I missing a library or something? I tried to install the latest java sdk to see if it would give me something but I have had no luck. Can someone help me out?

That JavaScript which is in Unity is not “real” JavaScript. Community call for it “UnityScript” but this is not the same scripting language what you think. Here you have to code differently than in original language.

Look here for better understanding: http://wiki.unity3d.com/index.php?title=UnityScript_versus_JavaScript