Uncaught Reference Error in Javascript & undefined [duplicate]

Question

Consider:

var myString = new String("Hello world");
alert(myString.noSuchValue); // undefined

alert(myshit);  // This results in error, and not the above one

Both of them, i.e.

• property noSuchValue on object myString,
• variable myshit

are undefined.

But why do I get an error for myshit and not for the object property case?

Answer 1

You can obtain the proper answer from the ECMAScript specs, but I'll summarize it in the following example:

var data= myObj.prop1;

The expected behavior is:

• if myObj (the base reference) does not exist, throw a ReferenceError.
• if the base exists, but the property not, return undefined