Does JavaScript pass by reference? [duplicate]

Answer 1

JavaScript is pass by value.

For primitives, primitive's value is passed. For Objects, Object's reference "value" is passed.

Example with Object:

var f1 = function(inputObject){
    inputObject.a = 2;
}

var f2 = function(){
    var inputObject = {"a": 1};
    f1(inputObject);
    console.log(inputObject.a);
}

Calling f2 results in printing out "a" value as 2 instead of 1, as the reference is passed and the "a" value in reference is updated.

Example with primitive:

var f1 = function(a){
    a = 2;
}
var f2 = function(){
    var a = 1;
    f1(a);
    console.log(a);
}

Calling f2 results in printing out "a" value as 1.