/javascript-call-apply

JavaScript-call-apply

Primary LanguageHTML

What is the difference between call and apply?

CALL

Call a function with the specified arguments. You can use call, if you know how many argument are going to pass to the functions.

APPLY

Call a function with argument provided as an array. You can use apply if you don't know how many argument are going to pass to the functions.

Both (call and apply) are using to call a functions.

Here is an advantage over apply and call. The .call() method is little bit faster than .apply() method.

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>The Difference Between Call and Apply in JavaScript</title>
    <script>
        var var1 = {myName: "ABC", };

        var var2 = {myName: "XYZ"};

        function preview(par1, par2) {
            alert(this.myName + '-' + par1 + '-' + par2);
            console.log(this.myName, par1, par2);
        }
		
        //using call as given below
        preview.call(var1, "First", "Second"); //output: ABC First Second

        //using apply as given below
        preview.apply(var2, ["First", "Second"]); //output: XYZ First Second

        //using basic as given below
        preview("First", "Second");//output: undefined "First", "Second"
    </script>
</head>
<body>
    <div>
        <h3>Refresh the page and see the alert result or go to console window and see the result.</h3>
    </div>
</body>
</html>

ScreenShot