Node.js console.time() Method

The console.time() method is the console class of Node.js. It is used to starts a timer that is used to compute the time taken by a piece of code or function. The method console.timeEnd() is used to stop the timer and output the elapsed time in milliseconds to stdout. The timer can be accurate to the sub-millisecond.

Syntax

console.time( label )

Parameter: This method accepts a single parameter label that can be passed in the method as a parameter and if the label is not passed default label is automatically given to the method. The label can different for different functions or pieces of code.

Below examples illustrate the working of console.time() method in Node.js:

Example 1:

// Node.js program to demonstrate the
// console.time() method

// Sample function
function addCount() {
  // Variable declaration
  var sum = 0;

  for (var i = 1; i < 100000; i++) {
    // Adding i to the sum variable
    sum += i;
  }

  // Return sum value
  return sum;
}

// Starts the timer
console.time();

// Function call
addCount();

// Ends the timer and print the time
// taken by the piece of code
console.timeEnd();

Output:

default: 8.760ms

Example 2:

// Node.js program to demonstrate the
// console.time() method

// Sample function
function addCount() {
  // Variable declaration
  var sum = 0;
  for (var i = 1; i < 100000; i++) {
    // Adding i to the sum variable
    sum += i;
  }
  return sum; // returning sum
}

var timetaken = "Time taken by addCount function";

// Starts the timer. The label value is timetaken
console.time(timetaken);

addCount(); // function call

// Ends the timer and print the time
// taken by the piece of code
console.timeEnd(timetaken);

Output:

Time taken by addCount function: 7.380ms

Example 3: This example using the different label for different functions simultaneously.

// Node.js program to demonstrate the
// console.time() method

// Sample function
function addCount() {
  var sum = 0; // Variable declaration
  for (var i = 1; i < 100000; i++) {
    sum += i; // Adding i to the sum variable
  }
  return sum; // returning sum
}

function countTime() {
  var timetaken = "Time taken by addCount function";

  // Starts the timer, the label value is timetaken
  console.time(timetaken);

  console.log(addCount()); // function call

  // Ends the timer and print the time
  // taken by the piece of code
  console.timeEnd(timetaken);
}

var label2 = "Time taken by countTime function";

// Starts the timer, the label value is label2
console.time(label2);

countTime(); // function call

// Ends the timer and print the time
// taken by the piece of code
console.timeEnd(label2);

Output:

4999950000
Time taken by addCount function: 24.884ms
Time taken by countTime function: 25.928ms

Reference: https://nodejs.org/docs/latest-v11.x/api/console.html#console_console_time_label