Jquery plugin, What is this returning?

Question

Can someone explain what kind of value the following is actually returning.

I understand the code up until the return part. Isn't it just a bunch of comparisons? What kind of value would come back? It would make sense to me if there was an if statement or something. hopefully my question makes sense.

I am not asking for the actual value being returned but more of the concept behind using the return, thanks.

$.fn.is_on_screen = function(){

    var win = $(window);

    var viewport = {
        left : win.scrollLeft()
    };
    viewport.right = viewport.left + win.width();

    var bounds = this.offset();
    bounds.right = bounds.left + this.outerWidth();

    return (!(viewport.right < bounds.left || viewport.left > bounds.right));
};

It returns boolean value true or false .... That signifies the method signature is_on_screen. — Runcorn
– Runcorn, Commented Feb 13, 2015 at 4:12

Alvaro Flaño Larrondo · Accepted Answer · 2015-02-13 04:13:23Z

1

When a function is returning a comparison it is returning a boolean.

answered Feb 13, 2015 at 4:13

Alvaro Flaño Larrondo

5,7402 gold badges31 silver badges50 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

RiddleMeThis Over a year ago

So is that like the same as... using an if statement like if(viewport.right < bounds.left || viewport.left > bounds.right){return:true}

Alvaro Flaño Larrondo Over a year ago

Yes, but it would be return:false because it has a ! before the comparison. The function first defines the variables and then makes the comparison using those variables.

RiddleMeThis Over a year ago

so it seems like a shortcut for if(...){return:true;}else{return:false;} correct?

Alvaro Flaño Larrondo Over a year ago

Right. It is very common to use it.

PRAH Over a year ago

@user3204142 - if() is a condition which check if its true it will execute whatever inside it. where as "return" is used to return the value when function is executed. return can be anything, number, string, Boolean or function. I am not expert in explaining things but I hope you understand my point.

Collectives™ on Stack Overflow

Jquery plugin, What is this returning?

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related