Javascript this Keyword With Example
In this article, we will see about javascript this keyword with example.
What is this Keyword
- this is a special keyword present inside every constructor function & method.
- this is a reference variable, which always points to the object with which we are currently working
- It is used to access members(i.e attributes & behaviors) of the currently working object.
Example code
function Rectangle(width, height){
this.width = width;
this.height = height;
this.getArea = function()
{
return this.width*this.height;
} }
var rect1 = new Rectangle(5,5);
document.write(rect1.getArea());
document.write("<br/>");
var rect2 = new Rectangle(6,6);
document.write(rect2.getArea());
Output:
25
36
- Here we have the create function “Rectangle” with passing two-parameter (width, height).
- In the function, we assign the width value to this. width and height value to this.height.
- Then we create another function within the “Rectangle” function() and return this.width * this.height value inside the function.
- We need to create a variable to call the function as in the above code. Here, we create variable ‘rect1’ and then call the Rectangle() function by passing two arguments (5,5).
- Then we need to print the variable to call the getArea() function because the geArea() function has a return value.