Discovering the Console in JavaScript

Written by germancutraro | Published 2018/01/28
Tech Story Tags: javascript | console | javascript-console | germancutraro | programming

TLDRvia the TL;DR App

The console object in JavaScript is fundamental piece when we are development ours projects.

‼️ You can go to my Github to find JavaScript examples. ‼️

If we type in our Google Chrome Developer Tools, in the console tag, the word: console you can see that is an object that is inside de global window object:

So you can access the console object from the window object.

window.console

But is not necessary πŸ‘“

Let’s get to know her evenΒ more:

Print in the console:Β πŸ”ˆ

_// Printing text_console.log('Hi!');

_// Printing a variable_const PI = Math.PI;console.log(PI);

// Expresionsconsole.log(2 + 4);console.log(`PI value: ${PI}`);

// Comparingconsole.log(null === undefined);console.log(3 > 2);console.log(typeof NaN);console.log(true || false);console.log(true && false);

// Ternary Operatorconsole.log( (3 > 2) ? 'Three!' : 'Two!');

Result: πŸ“

Print an error: ❌

console.error('Error!');

Result: πŸ“

Print a warning message: ⚠️

console.warn('Be careful')

Examining a object:Β πŸ”¦

console.dir(document);console.dir({a: 5});

Result: πŸ“

Assertion: β›³

function isEqual(x, y) {console.assert(x === y, { "message": "x is not equal than y","x": x,"y": y });}isEqual(10, 5);

Clear: ⬜️

console.clear();

Result: will be the console empty. πŸ“

Table Output:Β πŸ“‹

const users = [{name: 'Nick', age: 33},{name: 'Jessica', age: 23}];console.table(users);

Result: πŸ“

Time: 〽️

const users = [10, 20, 30];console.time('performance');const gThan10 = users.filter(n => n > 10);console.log(gThan10);console.timeEnd('performance');

Result: πŸ“

Group: πŸ“¦

console.group('numbers');console.log(1);console.log(2);console.log(3);console.groupEnd('numbers');

Thank you 😊!


Published by HackerNoon on 2018/01/28