Question

I am a little perplexed about what is going on with my code, here is what I have so far:

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

Person.prototype.getName = this.name;
Person.prototype.displayName = function() {
    return this.name;
}


var Sethen = new Person("Sethen");

console.log(Sethen.getName);
console.log(Sethen.displayName());

I am curious as to why getName doesn’t give me the this.name value and only logs blank, while the displayName method gives me the correct value. getName is a property of my prototype object, so my thought process was that I could grab it like this.

Why does getName not log the value of Sethen? How would I go about grabbing that information like a regular property? Must I use a method?

Answer 1

Because the value of this isn’t what you think it is when that code is run. this is probably equal to the global object (i.e. window).

Since you’re calling displayName and setting the context by prefixing it with an instance of the Person object, this is set correctly inside of the function and you get the person’s name out.

Of course, you could always access the name property directly (Sethen.name).