1.4 Printing to Console

1.4 Printing to Console What the Heck is the Console?Getting Started with Console Possibilities with Console .assert().log({}).table().time(__label__)Practice

1.4 Printing to Console

Console Meme

Me after writing Hello World with JavaScript:

What the Heck is the Console?

The console is the browser's built in debugger.

The console is your best friend for many reasons:

It is faster and easier to use than other tools as well as being error free.

It is a multi-purpose and somewhat generic tool.

It is the most common debugging method used in JavaScript.

It logs error messages, so you can easily debug them.

Getting Started with Console

To log (←send message) to console, it is written as:


console.log("__insert_message_here__");

To find out all the possible options that console has to offer, it is written as:


console.log(console);

Possibilities with Console

.assert()

💡

This section would make more sense after you learn conditional. So, if you don't get it right now, don't worry about it.

When you want to log something that is false, you use:


console.assert(__conditional__, 'user is not logged in');

So what is going on?

If some kind of conditional (← something that is defined as true or false) is placed in place of __conditional__ and it has the value of false, then an error will pop up in the console, telling you the conditional is false.

.log({})

This provides labels for things that you desire to log.


// note: foo and bar are just variables
let foo = 23;
let bar = 24;
console.log(foo, bar); // output: 23 24
console.log({foo, bar}); // output: { foo: 23, bar: 24 }

.table()

This provides you with a more organized output than console.log({}).


let foo = 23;
let bar = 24;
console.table([foo, bar]);

The console should provide you with a table like this:

.time(label)

This starts a timer and console.timeLog() will log the time elapsed since that timer started.


console.time('time');
console.timeLog('time');

Practice

You can add practice problems here if you want. Follow the format below.

💻 Template code

✅ Solution code

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1.5 Data Types

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