The 'this' Keyword

This keyword

'this' keyword refers to the owner object.

- when we use this keyword alone it refers to the window object.
       eg. console.log(this);

- In normal function, this refers the global object (window object).
    eg.

    <script>

        function video(){

            this.title = "Roar"; //Here title belong to window

            this.length = 3.4;

        }

        let v = new video();

        console.log(`Title : ${v.title} , Length : ${v.length}`);  

        //here we try to access variables of video function

    </script>

- In a method, It refers the the parent object.

    <script>

        let book = {

            title: "programming in js",

            author : "abcd",

            publisher : "forouzan",

            displayDetail : function(){

                console.log(`title : ${this.title}, 

                author : ${this.author}, publisher : ${this.publisher}`);

                console.log(this); // Now this refers book object

            }

        };

        book.displayDetail();

    </script>

output: title : programming in js, author : abcd, publisher : forouzan