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JavaScript Understanding "this" in JavaScript

Rizwan Renesa
Rizwan Renesa
7,805 Points
Posted by Rizwan Renesa
Rizwan Renesa
7,805 Points

Why can't we call the function using foo() ?

function logTeams(){ console.log(this.soccerTeams); }

Portland.foo = logTeams;

Portland.foo(); foo();

Why can't we call the function using foo()? There was a point in the video where this was done and the console spitted out error?

1 Answer

andren
andren
28,558 Points
andren
andren
28,558 Points

Because no function called foo exists.

In the above code you add a property to the Portland object called foo and set it equal to a function, since this property stores a function you can call it like a function Portland.foo(), but that doesn't change the fact that it's just a property stored in the Portland object. foo by itself is not a variable or function that exists on its own.

Basically if I had an object like this:

var example = {
    message: "Hello World!"
}

I could access that message like this example.message, however I could not simply type message and access it. Since message would not be a variable that exists on its own, it's just a property inside the object. The exact same thing is true with foo.