JavaScript Console Methods

Table of Contents

JavaScript console Methods :

console.assert()

The console.assert() method writes a message to the console, but only if an expression evaluates to false.


console.assert(document.getElementById("demo")),
"You have no element with ID 'demo'");

//Output
//Assertion failed : You have no element with ID 'demo'

console.clear()

The console.clear() method clears the console. It will also write a message in the console: “Console was cleared”.


console.clear();

//Output
// console was cleared

console.count()

Writes to the console the number of times that particular console.count() is called. You can add a label that will be included in the console view.


console.count("myLabel");
console.count("myLabel");

//Output
// myLabel : 1
// myLabel : 2

console.error()

he console.error() method writes an error message to the console.The console is useful for testing purposes.


console.error("You made a mistake");

//Output
// You made a mistake

console.group()

The console.group() method indicates the start of a message group.All messages will from now on be written inside this group.


console.log("Hello world");
console.group();
console.log("this time inside a group!");

//Output
// Hello world!
// console.group
//    this time inside a group!

console.groupCollapsed()

The console.groupCollapsed() method indicates the start of a collapsed message group. Click the expand button to open the message group.


console.groupCollapsed();
console.log("this time inside a group!");

//Output
// console.groupCollapsed
// this time inside a group!

console.groupEnd()

The console.groupEnd() method indicates the end of a message group.


console.log("Hello world");
console.group();
console.log("this time inside a group!");
console.groupEnd();
console.log("and we are back.");

//Output
// Hello world!
// console.group
//    this time inside a group!
//  and we are back.

console.table()

The console.table() method writes a table in the console view. The first parameter is required, and must be either an object, or an array, containing data to fill the table.


console.table(["Audi", "Volvo", "Ford"]);

console.info()

The console.info() method writes a message to the console.


console.info("I Like Coding");

// Output 
//I Like Coding

console.log()

The console.log() method writes a message to the console. The console is useful for testing purposes.


console.log("I Like Coding");

// Output 
//I Like Coding

console.time()

Use the console.time() method to start the timer. The console.timeEnd() method ends a timer, and writes the result in the console view.


console.time();
for(i=0; i < 100000; i++){
  // some code
}
console.timeEnd();
// Output 
// default : 2.491943359375 ms

console.warn()

The console.warn() method writes a warning to the console.


console.warn("This is a warning!");

// Output 
//  This is a warning!

I hope you like this JavaScript console Methods article.