问题:

Given a very simple js object constructor and its prototype...

    function MyTest(name)
    {
        this.name = name;
    }

    MyTest.prototype =
    {
        getName: function()
        {
            var myName = this.name;
            return myName;
        },
        myMethod: function()
        {
            //
        }
    }

Now, in myMethod, is there any difference between using "this.getName" and "this.name"?

Thanks

回答1:

Depends on whether name is an object nor a primitive (boolean, string, int).

If name is a primitive/ string, and you use this.getName(), you won't be able to modify the value of this.name by doing this (assuming this.name = "Billy")

this.getName() = "213" //this.name still has a value of "Billy"

If name is an object this.name = { firstName: "Billy", lastName: "Bob"};

this.getName().firstName = "Willy"; //this.name now has a value of { firstName: "Willy", lastName: "Bob"}

This is due to JavaScript passing primitives by value, but passing objects by reference.

回答2:

Using the function is slightly slower, but allows you to change how it works in the future (or to do so in another object type that inherits from this one).