The console module provides a simple debugging console that is provided by web browsers which export two specific components:
- A Console class that can be used to write to any Node.js stream. Example: console.log(), console.error(), etc.
- A global console that can be used without importing the console. Example: process.stdout, process.stderr, etc.
The console.profile() (Added in v8.0.0) method is an inbuilt application programming interface of the ‘console‘ module which doesn’t display anything unless used in the inspector. It starts a JavaScript CPU profile with an optional label until console.profile() is called. The profile is then added to the Profile panel of the inspector.
Note: The global console methods are neither consistently synchronous nor consistently asynchronous.
Syntax:
console.profile([label])
Parameters: This function accepts a single parameter as mentioned above and described below:
label <string>: It accepts the label name that is further to be used in the inspector.
Return Value: It doesn’t print anything in the console instead, starts a JavaScript CPU profile in Inspector.
The Below examples illustrate the use of a console.profile() method in Node.js.
Example 1: Filename: index.js
// Node.js program to demonstrate the // console.profile() Method // Starting MyLabel console profile console.profile( 'MyLabel' );
// Doing some task for (let i = 0; i < 4; i++) {
// Printing some task
console.log( 'Doing task no:' , i);
} // Finishing MyLabel profile console.profileEnd( 'MyLabel' );
|
Run the index.js file using the following command:
node index.js
Output in Console:
Doing task no: 0 Doing task no: 1 Doing task no: 2 Doing task no: 3
Output in Inspector:
Example 2: Filename: index.js
// Node.js program to demonstrate the // console.profile() Method // New profile function function newProfile(callback) {
try {
// Doing some task
for (let i = 1; i < 4; i++) {
console.log( 'Working on task:' , i);
callback();
}
} catch {
// Prints if there is error
console.error( 'error occurred' );
}
} // Starting newProfile() console profile console.profile( "newProfile()" );
// Calling newprofile() newProfile( function alfa() {
// Finishing profile
console.profileEnd();
}); |
Run the index.js file using the following command:
node index.js
Output in Console:
Working on task: 1 Working on task: 2 Working on task: 3
Output in Inspector:
Reference: https://nodejs.org/api/console.html#console_console_profile_label