freeCodeCamp/guide/english/meta/free-code-camp-javascript-style-guide/index.md

---
title: Free Code Camp JavaScript Style Guide
---
<small>or How Cool People Write JavaScript.</small>

## Indent

Always Use Two Spaces  
No hard tabs, ever. No really, just don't do it.

## Curly Braces

Always use curly braces when using the keywords `if/else/else if`. This prevents a lot of ambiguity and will prevent syntax errors in some edge cases.

Bad:

    if (foo) bar();

Good:

    if (foo) { bar(); }

## Curly Braces Everywhere!

Space After `function` Keyword, Except in Anonymous Functions

Good:

    function foo() {
    }

    var foo = function() {
      // ...
    };

Bad:

    function foo ()
    {
      // ...
    }

    var foo = function () {
      // ...
    };

## Comments

*   no inline comments
*   single space after `//`
*   Do not use multiline comment `/* */`, we are reserving these for use with jsDocs.

## Keywords

*   space immediately after if, else, while, etc
*   opening curly brace should always be on the same line.

Good:

    if (true) {
     // do the thing
    }

Bad:

    if(true)
    {
     // do the thing
    }

## Else

Avoid else and "end early". In JavaScript there is often a lot of indenting (usually when dealing with async code and named "callback hell"). Anything you can do reduce the number of indents should be done. One thing is to <a href='http://blog.timoxley.com/post/47041269194/avoid-else-return-early' target='_blank' rel='nofollow'>avoid the else</a> keyword.

This also has the side effect of making code cleaner and easier to read.

Bad:

    someAsynFunc(function(err, data) {
      if (err) {
        callback(err);
      } else {
        // do stuff with data
      }
    });

Good:

    someAsynFunc(function(err, data) {
      if (err) {
        return callback(err);
      }
      // do stuff with data
      // saves one indent
    });

## Long Strings

Long multiline strings should be in one of two forms:

    var longString =
      ‘long strings should ‘ +
      ‘be in this form, with the ‘ +
      ‘operator ending the line’;

    var foo = 'bar';

    var longString = [
      'long strings with variables such as ',
      foo,
      'should ',
      'be in this form, an array of strings ',
      'that are joined with the join array instance method',
    ].join('');

...more to come