Node.js console.profile() Method

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

javascript

// 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:

Output in Inspector

Example 2: Filename: index.js

javascript

// 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:

Output in Inspector

Reference: https://nodejs.org/api/console.html#console_console_profile_label