Skip to main content

Make use of JavaScript console methods

When I say JavaScript console methods, the one and only thing that hit most of our mind is console.log() and we use it a lot and only that some might be familiar with error() and debug(). Did you ever think of checking if there are any other methods available in console other than log? Most of us don't do that, but knowing those methods might have saved lot of our development time. In this post I will show you some of the console methods which will be very useful in our day to day coding.

Log based on condition

console.assert(assertion, log_message);
To print something on the console only if the assertion failed - assertion can be any expression which returns a boolean.
Note: In chrome this log will print as an error with message saying "Assertion failed:" with the log_message passed. In FireFox its a normal log message.

Log number of occurrence 

If we want to count something, it may be a click, may be a callback, or event triggers. We don't need to create a var and increment and then log. We can simply use console.count('my_clicks') and console will do the counts for you and print the same. Wow! Nice right? But see below for another handy method which we missed.

Log time taken

An easy way for developers to see how much time a logic is running. Given a label name this method will print the amount of time taken in milliseconds between the time() and timeEnd() method for that particular label.

Trace who triggered this function

Did you ever care to find which action is triggering a particular action or event? If yes, trace() is a wonderful console method which will give you all the levels of trace till the line where you called trace() method. This will give the file names with line numbers where the trigger came from. A big time saver right?

Do you know that you can use c like syntax in console messages?

var test = ['one','two']
console.log("This is an object %o and its length is %d", test, test.length);

List of substitutions you can use:

  • %o or %O : Outputs a JavaScript object. Clicking the object name opens more information about it in the inspector.
  • %d or %i   : Outputs an integer. Number formatting is supported, for example  console.log("Foo %.2d", 1.1) will output the number as two significant figures with a leading 0: Foo 01
  • %s : Outputs a string.
  • %f  : Outputs a floating-point value. Formatting is supported.  
If you find some other useful methods, let me know in the comments section and check the source link for some more methods, details and browser support.



Post a Comment

Popular posts from this blog

TataSky Refresh after Recharge - Activate after Recharge

If you are using TataSky and doing recharge occasionally and that too after disconnection, this post will be very helpful for you.
Most of the time you will not get the channels listed as soon as you make the payment. It will display message to Subscribe for that channel.
You can easily get channels back by simply giving a missed a call from your registered mobile number.

Note: Make sure your TV and SetupBox is on and showing the error message

Give missed call to +91 80892 80892 (Soft Refresh)wait for 1 minute and
If still not active then try giving missed call to +91 90405 90405 (Heavy Refresh).
Ad:Planning to buy a Best low budget Smart TV? Consider Mi LED Smart TV 4A PRO - You can get this TV as low as for 11,500 Rs - which has Bluetooth, WiFi, Android, 8 GB storage and good customer ratings (4.4/5). Note: Price based on offers, click on the link to see current price on the web page If the above step did not help you, there might be something else going wrong, please contact TataSky S…

Installing Cordova on Ubuntu 16.04 without Android Studio

Apache Cordova is a platform to build mobile applications using JavaScript, HTML5 and CSS.

When I was trying to install cordova for creating an android application on my Ubuntu 16.04 I was facing lot of versioning and dependency problems. So in this post I will be discussing about all those issues and the solution that worked for me. All the steps are via command line and so no android studio. I don't want to install GB's of files to just use sdk.
Install latest version of node and npmInstall CordovaInstall android SDK (Command line)Setting environment variablesCreating android plaformCreating and running first app Installing latest version of nodejs
By default ubuntu 16.04 has a stable version of nodejs added in its own repository. So to install latest version from Ubuntu itself you can simply use apt commad as follows.
$ sudo apt update $ sudo apt install nodejs But when I was using this version (4.2.6 is the latest stable version available when I was trying) I got some…

My First Post

After lot of thinking and research me too started a blog finally to share my knowledge :-).

Not everybody know everything but also everybody else don't know what we know. So lets share and gain knowledge with Win Win approach.