HTML | DOM console.assert( ) Method

The console.assert() method in HTML is used to write a message for user on the console only if the expression evaluates to false. The expression and the message are sent as parameters to the console.assert() method.

Syntax:

console.assert( expression, message )

Parameters: This method accept two parameters as mentioned above and described below:

  • expression: It is a Boolean expression which denotes the message or object to write to the console. It is required parameter.
  • message : It is a string or an object which denotes the message or object to write to the console. It is required parameter.

Below program illustrates the console.assert() method in HTML:

Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

<!DOCTYPE html>
<html>
    <head
        <title>DOM console.assert() Method</title
        <style
            h1 { 
                color:green; 
            
            h2 {
                font-family: Impact;
            }
            body { 
                text-align:center; 
            
        </style
    </head>
    <body>
        <h1>GeeksforGeeks</h1
        <h2>DOM console.assert() Method</h2
        <p>To view the message in the console press the F12
        key on your keyboard.</p>
        <script>
            console.assert(document.getElementById("MyElement"), 
            "There is no element with the ID 'MyElement'");
        </script>
    </body>
</html>                    

chevron_right


Output:


See console view to press F12 Key:

Example 2: Displaying an object while using console.assert() method

filter_none

edit
close

play_arrow

link
brightness_4
code

<!DOCTYPE html>
<html>
    <head
        <title>DOM console.assert() Method</title
        <style
            h1 { 
                color:green; 
            
            h2 {
                font-family: Impact;
            }
            body { 
                text-align:center; 
            
        </style
    </head>
    <body>
        <h1>GeeksforGeeks</h1
        <h2>DOM console.assert( ) Method</h2
        <p>To view the message in the console press the F12 key on 
             your keyboard.</p>
        <script>
            var MyElement = { Product : "Coca Cola", Type : "Beverage" };
            console.assert(document.getElementById("MyDemo"), MyElement);
        </script>
    </body>
</html>                    

chevron_right


Output:


See console view on Pressing the F12 Key:

Supported Browsers: The browser supported by console.assert() method are listed below:

  • Google Chrome
  • Apple Safari
  • Firefox 28.0
  • Opera
  • Internet Explorer


My Personal Notes arrow_drop_up

I am a technology enthusiast who has a keen interest in programming I am pursuing Engineering in Computer Science from GEU, Dehradun I like to unwind by watching movies and English sitcomsI have a keen interest in music

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.