Scope in javascript acting weird

Question

Object are passed with their reference in javascript. Meaning change in that object from any where should be reflected. In this case, the expected output was {} for console.log(

Answer 1

The variable 'a' in the context of your function is not the same as the 'a' variable outside the function. This code is semantically equivalent to yours:

function change(foo,bar) {
    foo.x = 'added';
    foo = bar;//assigning foo as {} to bar
}
a={}
b={}
change(a,b);
console.log(a); //expected {} but output {x:'added'}
console.log(b)

It's obvious in this case that the 'foo' variable only exists inside the function, and doing foo = bar doesn't change a as the reference is passed by value.