“var variable” returns undefined?

Question

When I run \"var variable = true;\" in chrome console I get \"undefined\" returned:

> var variable = true;
undefined

But when I run with

Answer 1

var x = y; is a statement which returns no value. In the WebKit JS console, a statement that returns no value will show undefined as the result, e.g.

> if(1){}
undefined
> ;
undefined
> if(1){4}  // this statement returns values!
4

The assignment is an expression which returns the value of the LHS. That means, this expression statement has a return value, and this will be shown.