Airbnb JavaScript TypeScript Style Guide(unofficial) {

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Airbnb JavaScript TypeScript Style Guide(unofficial) {

*A mostly reasonable approach to TypeScript

Types
Objects
Arrays
Strings
Functions
Properties
Variables
Hoisting
Comparison Operators & Equality
Blocks
Comments
Whitespace
Commas
Semicolons
Type Casting & Coercion
Naming Conventions
Accessors
Class - Class members
Events
Modules
jQuery
ECMAScript 5 Compatibility
Testing
Performance
Resources
In the Wild
Translation
The JavaScript Style Guide Guide
Chat With Us About Javascript
Contributors
License

Types

Types should be used whenever necessary.

// bad
var foo = 1;

// good
var foo: number = 1;

Arrays should be defined with the help of Generics as Array<type> instead of type[].

// bad
var foo = [1, 2, 3];

// good
var foo: Array<number> = [1, 2, 3];

Use the any type sparingly, it is always better to define an interface.

// bad
var person: any = {
    name: string
};

// good
interface IPerson {
    name: string
}

var person: IPerson = {
    name: 'André König'
};

Always define the return type of functions (even if nothing will be returned: void)

// bad
function foo () {
    return 'bar';
}

// good
function foo () : string {
    return 'bar';
}

Always define the types of variables/parameters

// bad
function (foo) {
    console.log(foo);
}

// good
function (foo: string) {
    console.log(foo);
}

Primitives: When you access a primitive type you work directly on its value.
- string
- number
- boolean
- null
- undefined
```
var foo: number = 1;
var bar: any = foo;

bar = 9;

console.log(foo, bar); // => 1, 9
```

Complex: When you access a complex type you work on a reference to its value.

object
array
function

var foo: Array<number> = [1, 2];
var bar: any = foo;

bar[0] = 9;

console.log(foo[0], bar[0]); // => 9, 9

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Objects

Use the literal syntax for object creation.

// bad
var item: Object = new Object();

// good
var item: Object = {};

Don't use reserved words as keys. It won't work in IE8. More info.

// bad
var superman: Object = {
    default: { clark: 'kent' },
    private: true
};

// good
var superman: Object = {
    defaults: { clark: 'kent' },
    hidden: true
};

Use readable synonyms in place of reserved words.

// bad
var superman: Object = {
    class: 'alien'
};

// bad
var superman: Object = {
    klass: 'alien'
};

// good
var superman: Object = {
    type: 'alien'
};

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Arrays

Use the literal syntax for array creation.

// bad
var items: Array<string> = new Array();

// good
var items: Array<string> = [];

Use Array#push instead of direct assignment to add items to an array.

var someStack: Array<string> = [];

// bad
someStack[someStack.length] = 'abracadabra';

// good
someStack.push('abracadabra');

When you need to copy an array use Array#slice. jsPerf

var len: number = items.length;
var itemsCopy: Array<number> = [];
var i: number;

// bad
for (i = 0; i < len; i++) {
    itemsCopy[i] = items[i];
}

// good
itemsCopy = items.slice();

To convert an array-like object to an array, use Array#slice.

function trigger() {
    var args = Array.prototype.slice.call(arguments);
    ...
}

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Strings

Use single quotes '' for strings.

// bad
var name: string = "Bob Parr";

// good
var name: string = 'Bob Parr';

// bad
var fullName: string = "Bob " + this.lastName;

// good
var fullName: string = 'Bob ' + this.lastName;

Strings longer than 80 characters should be written across multiple lines using string concatenation.

Note: If overused, long strings with concatenation could impact performance. jsPerf & Discussion.

// bad
var errorMessage: string = 'This is a super long error that was thrown because of Batman. When you stop to think about how Batman had anything to do with this, you would get nowhere fast.';

// bad
var errorMessage: string = 'This is a super long error that was thrown because \
of Batman. When you stop to think about how Batman had anything to do \
with this, you would get nowhere \
fast.';

// good
var errorMessage: string = 'This is a super long error that was thrown because ' +
  'of Batman. When you stop to think about how Batman had anything to do ' +
  'with this, you would get nowhere fast.';

When programmatically building up a string, use Array#join instead of string concatenation. Mostly for IE: jsPerf.

var messages: Array<Object>;
var length: number;
var i: number;

messages = [{
    state: 'success',
    message: 'This one worked.'
}, {
    state: 'success',
    message: 'This one worked as well.'
}, {
    state: 'error',
    message: 'This one did not work.'
}];

length = messages.length;

// bad
function inbox(messages) {
    var items: string = '<ul>';

    for (i = 0; i < length; i++) {
        items += '<li>' + messages[i].message + '</li>';
    }

    return items + '</ul>';
}

// good
function inbox(messages) {
    var items: Array<string> = [];

    for (i = 0; i < length; i++) {
        itemsList[i] = '<li>' + messages[i].message + '</li>';
    }

    return '<ul>' + itemsList.join('') + '</ul>';
}

For any string interpolation use ES6 template string

// good
var name: string = 'joe';
var message = `The name is ${name}.`;

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Functions

Function expressions:

// anonymous function expression
var anonymous = function() {
    return true;
};

// named function expression
var named = function named() {
    return true;
};

// immediately-invoked function expression (IIFE)
(function() {
    console.log('Welcome to the Internet. Please follow me.');
})();

Never declare a function in a non-function block (if, while, etc). Assign the function to a variable instead. Browsers will allow you to do it, but they all interpret it differently, which is bad news bears.

Note: ECMA-262 defines a block as a list of statements. A function declaration is not a statement. Read ECMA-262's note on this issue.

// bad
if (currentUser) {
    function test() {
        console.log('Nope.');
    }
}

// good
var test;
if (currentUser) {
    test = function test() {
        console.log('Yup.');
    };
}

Never name a parameter arguments. This will take precedence over the arguments object that is given to every function scope.

// bad
function nope(name, options, arguments) {
    // ...stuff...
}

// good
function yup(name, options, args) {
    // ...stuff...
}

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Properties

Use dot notation when accessing properties.

var luke = {
    jedi: true,
    age: 28
};

// bad
var isJedi = luke['jedi'];

// good
var isJedi = luke.jedi;

Use subscript notation [] when accessing properties with a variable.

var luke = {
    jedi: true,
    age: 28
};

function getProp(prop) {
    return luke[prop];
}

var isJedi = getProp('jedi');

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Variables

Always use var to declare variables. Not doing so will result in global variables. We want to avoid polluting the global namespace. Captain Planet warned us of that.
```
// bad
superPower = new SuperPower();

// good
var superPower = new SuperPower();
```

Use one var declaration per variable. It's easier to add new variable declarations this way, and you never have to worry about swapping out a ; for a , or introducing punctuation-only diffs.

// bad
var items = getItems(),
    goSportsTeam = true,
    dragonball = 'z';

// bad
// (compare to above, and try to spot the mistake)
var items = getItems(),
    goSportsTeam = true;
    dragonball = 'z';

// good
var items = getItems();
var goSportsTeam = true;
var dragonball = 'z';

Declare unassigned variables last. This is helpful when later on you might need to assign a variable depending on one of the previous assigned variables.

// bad
var i, len, dragonball,
    items = getItems(),
    goSportsTeam = true;

// bad
var i;
var items = getItems();
var dragonball;
var goSportsTeam = true;
var len;

// good
var items = getItems();
var goSportsTeam = true;
var dragonball;
var length;
var i;

Assign variables at the top of their scope. This helps avoid issues with variable declaration and assignment hoisting related issues.

// bad
function() {
    test();
    console.log('doing stuff..');

    //..other stuff..

    var name = getName();

    if (name === 'test') {
        return false;
    }

    return name;
}

// good
function() {
    var name = getName();

    test();
    console.log('doing stuff..');

    //..other stuff..

    if (name === 'test') {
        return false;
    }

    return name;
}

// bad
function() {
    var name = getName();

    if (!arguments.length) {
        return false;
    }

    return true;
}

// good
function() {
    if (!arguments.length) {
        return false;
    }

    var name = getName();

    return true;
}

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Hoisting

Variable declarations get hoisted to the top of their scope, but their assignment does not.

// we know this wouldn't work (assuming there
// is no notDefined global variable)
function example() {
    console.log(notDefined); // => throws a ReferenceError
}

// creating a variable declaration after you
// reference the variable will work due to
// variable hoisting. Note: the assignment
// value of `true` is not hoisted.
function example() {
    console.log(declaredButNotAssigned); // => undefined
    var declaredButNotAssigned = true;
}

// The interpreter is hoisting the variable
// declaration to the top of the scope,
// which means our example could be rewritten as:
function example() {
    var declaredButNotAssigned;
    console.log(declaredButNotAssigned); // => undefined
    declaredButNotAssigned = true;
}

Anonymous function expressions hoist their variable name, but not the function assignment.

function example() {
    console.log(anonymous); // => undefined

    anonymous(); // => TypeError anonymous is not a function

    var anonymous = function() {
        console.log('anonymous function expression');
    };
}

Named function expressions hoist the variable name, not the function name or the function body.

function example() {
    console.log(named); // => undefined

    named(); // => TypeError named is not a function

    superPower(); // => ReferenceError superPower is not defined

    var named = function superPower() {
        console.log('Flying');
    };
}

// the same is true when the function name
// is the same as the variable name.
function example() {
    console.log(named); // => undefined

    named(); // => TypeError named is not a function

    var named = function named() {
        console.log('named');
    }
}

Function declarations hoist their name and the function body.

function example() {
    superPower(); // => Flying

    function superPower() {
        console.log('Flying');
    }
}

For more information refer to JavaScript Scoping & Hoisting by Ben Cherry.

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Comparison Operators & Equality

Use === and !== over == and !=.
Comparison operators are evaluated using coercion with the ToBoolean method and always follow these simple rules:
- Objects evaluate to true
- Undefined evaluates to false
- Null evaluates to false
- Booleans evaluate to the value of the boolean
- Numbers evaluate to false if +0, -0, or NaN, otherwise true
- Strings evaluate to false if an empty string '', otherwise true
```
if ([0]) {
  // true
  // An array is an object, objects evaluate to true
}
```

Use shortcuts.

// bad
if (name !== '') {
  // ...stuff...
}

// good
if (name) {
  // ...stuff...
}

// bad
if (collection.length > 0) {
  // ...stuff...
}

// good
if (collection.length) {
  // ...stuff...
}

For more information see Truth Equality and JavaScript by Angus Croll.

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Blocks

Use braces with all multi-line blocks.

// bad
if (test)
    return false;

// good
if (test) return false;

// good
if (test) {
    return false;
}

// bad
function() { return false; }

// good
function() {
    return false;
}

If you're using multi-line blocks with if and else, put else on the same line as your if block's closing brace.

// bad
if (test) {
    thing1();
    thing2();
}
else {
    thing3();
}

// good
if (test) {
    thing1();
    thing2();
} else {
    thing3();
}

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Comments

Use /** ... */ for multi-line comments. Include a description, specify types and values for all parameters and return values.

// bad
// make() returns a new element
// based on the passed in tag name
//
// @param {String} tag
// @return {Element} element
function make(tag) {

    // ...stuff...

    return element;
}

// good
/**
 * make() returns a new element
 * based on the passed in tag name
 *
 * @param {String} tag
 * @return {Element} element
 */
function make(tag) {

    // ...stuff...

    return element;
}

Use // for single line comments. Place single line comments on a newline above the subject of the comment. Put an empty line before the comment.

// bad
var active = true;  // is current tab

// good
// is current tab
var active = true;

// bad
function getType() {
    console.log('fetching type...');
    // set the default type to 'no type'
    var type = this._type || 'no type';

    return type;
}

// good
function getType() {
    console.log('fetching type...');

    // set the default type to 'no type'
    var type = this._type || 'no type';

    return type;
}

Prefixing your comments with FIXME or TODO helps other developers quickly understand if you're pointing out a problem that needs to be revisited, or if you're suggesting a solution to the problem that needs to be implemented. These are different than regular comments because they are actionable. The actions are FIXME -- need to figure this out or TODO -- need to implement.

Use // FIXME: to annotate problems.

function Calculator() {

    // FIXME: shouldn't use a global here
    total = 0;

    return this;
}

Use // TODO: to annotate solutions to problems.

function Calculator() {

    // TODO: total should be configurable by an options param
    this.total = 0;

    return this;
}


**[⬆ back to top](#table-of-contents)**


## Whitespace

- Use soft tabs set to 4 spaces.

  ```typescript

  // bad
  function() {
  ∙var name;
  }

  // good
  function() {
  ∙∙∙∙var name;
  }
  ```

- Place 1 space before the leading brace.

  ```typescript
  // bad
  function test(){
      console.log('test');
  }

  // good
  function test() {
      console.log('test');
  }

  // bad
  dog.set('attr',{
      age: '1 year',
      breed: 'Bernese Mountain Dog'
  });

  // good
  dog.set('attr', {
      age: '1 year',
      breed: 'Bernese Mountain Dog'
  });
  ```

- Place 1 space before the opening parenthesis in control statements (`if`, `while` etc.). Place no space before the argument list in function calls and declarations.

  ```typescript
  // bad
  if(isJedi) {
      fight ();
  }

  // good
  if (isJedi) {
      fight();
  }

  // bad
  function fight () {
      console.log ('Swooosh!');
  }

  // good
  function fight() {
      console.log('Swooosh!');
  }
  ```

- Set off operators with spaces.

  ```typescript
  // bad
  var x=y+5;

  // good
  var x = y + 5;
  ```

- End files with a single newline character.

  ```typescript
  // bad
  (function(global) {
    // ...stuff...
  })(this);
  ```

  ```typescript
  // bad
  (function(global) {
    // ...stuff...
  })(this);↵
  ↵
  ```

  ```typescript
  // good
  (function(global) {
    // ...stuff...
  })(this);↵
  ```

- Use indentation when making long method chains. Use a leading dot, which
  emphasizes that the line is a method call, not a new statement.

  ```typescript
  // bad
  $('#items').find('.selected').highlight().end().find('.open').updateCount();

  // bad
  $('#items').
      find('.selected').
          highlight().
          end().
      find('.open').
          updateCount();

  // good
  $('#items')
      .find('.selected')
          .highlight()
          .end()
      .find('.open')
          .updateCount();

  // bad
  var leds = stage.selectAll('.led').data(data).enter().append('svg:svg').classed('led', true)
      .attr('width',  (radius + margin) * 2).append('svg:g')
      .attr('transform', 'translate(' + (radius + margin) + ',' + (radius + margin) + ')')
      .call(tron.led);

  // good
  var leds = stage.selectAll('.led')
      .data(data)
    .enter().append('svg:svg')
      .classed('led', true)
      .attr('width',  (radius + margin) * 2)
    .append('svg:g')
      .attr('transform', 'translate(' + (radius + margin) + ',' + (radius + margin) + ')')
      .call(tron.led);
  ```

- Leave a blank line after blocks and before the next statement

  ```typescript
  // bad
  if (foo) {
    return bar;
  }
  return baz;

  // good
  if (foo) {
    return bar;
  }

  return baz;

  // bad
  var obj = {
    foo: function() {
    },
    bar: function() {
    }
  };
  return obj;

  // good
  var obj = {
    foo: function() {
    },

    bar: function() {
    }
  };

  return obj;
  ```

**[⬆ back to top](#table-of-contents)**

## Commas

- Leading commas: **Nope.**

  ```typescript
  // bad
  var story = [
      once
    , upon
    , aTime
  ];

  // good
  var story = [
    once,
    upon,
    aTime
  ];

  // bad
  var hero = {
      firstName: 'Bob'
    , lastName: 'Parr'
    , heroName: 'Mr. Incredible'
    , superPower: 'strength'
  };

  // good
  var hero = {
    firstName: 'Bob',
    lastName: 'Parr',
    heroName: 'Mr. Incredible',
    superPower: 'strength'
  };
  ```

- Additional trailing comma: **Nope.** This can cause problems with IE6/7 and IE9 if it's in quirksmode. Also, in some implementations of ES3 would add length to an array if it had an additional trailing comma. This was clarified in ES5 ([source](http://es5.github.io/#D)):

> Edition 5 clarifies the fact that a trailing comma at the end of an ArrayInitialiser does not add to the length of the array. This is not a semantic change from Edition 3 but some implementations may have previously misinterpreted this.

  ```typescript
  // bad
  var hero = {
    firstName: 'Kevin',
    lastName: 'Flynn',
  };

  var heroes = [
    'Batman',
    'Superman',
  ];

  // good
  var hero = {
    firstName: 'Kevin',
    lastName: 'Flynn'
  };

  var heroes = [
    'Batman',
    'Superman'
  ];
  ```

**[⬆ back to top](#table-of-contents)**


## Semicolons

- **Yup.**

  ```typescript
  // bad
  (function() {
    var name = 'Skywalker'
    return name
  })()

  // good
  (function() {
    var name = 'Skywalker';
    return name;
  })();

  // good (guards against the function becoming an argument when two files with IIFEs are concatenated)
  ;(function() {
    var name = 'Skywalker';
    return name;
  })();
  ```

  [Read more](http://stackoverflow.com/a/7365214/1712802).

**[⬆ back to top](#table-of-contents)**


## Type Casting & Coercion

- Perform type coercion at the beginning of the statement.
- Strings:

  ```typescript
  //  => this.reviewScore = 9;

  // bad
  var totalScore = this.reviewScore + '';

  // good
  var totalScore = '' + this.reviewScore;

  // bad
  var totalScore = '' + this.reviewScore + ' total score';

  // good
  var totalScore = this.reviewScore + ' total score';
  ```

- Use `parseInt` for Numbers and always with a radix for type casting.

  ```typescript
  var inputValue = '4';

  // bad
  var val = new Number(inputValue);

  // bad
  var val = +inputValue;

  // bad
  var val = inputValue >> 0;

  // bad
  var val = parseInt(inputValue);

  // good
  var val = Number(inputValue);

  // good
  var val = parseInt(inputValue, 10);
  ```

- If for whatever reason you are doing something wild and `parseInt` is your bottleneck and need to use Bitshift for [performance reasons](http://jsperf.com/coercion-vs-casting/3), leave a comment explaining why and what you're doing.

  ```typescript
  // good
  /**
   * parseInt was the reason my code was slow.
   * Bitshifting the String to coerce it to a
   * Number made it a lot faster.
   */
  var val = inputValue >> 0;
  ```

- **Note:** Be careful when using bitshift operations. Numbers are represented as [64-bit values](http://es5.github.io/#x4.3.19), but Bitshift operations always return a 32-bit integer ([source](http://es5.github.io/#x11.7)). Bitshift can lead to unexpected behavior for integer values larger than 32 bits. [Discussion](https://github.com/airbnb/javascript/issues/109). Largest signed 32-bit Int is 2,147,483,647:

  ```typescript
  2147483647 >> 0 //=> 2147483647
  2147483648 >> 0 //=> -2147483648
  2147483649 >> 0 //=> -2147483647
  ```

- Booleans:

  ```typescript
  var age = 0;

  // bad
  var hasAge = new Boolean(age);

  // good
  var hasAge = Boolean(age);

  // good
  var hasAge = !!age;
  ```

**[⬆ back to top](#table-of-contents)**


## Naming Conventions

- Avoid single letter names. Be descriptive with your naming.

  ```typescript
  // bad
  function q() {
    // ...stuff...
  }

  // good
  function query() {
    // ..stuff..
  }
  ```

- Use camelCase when naming objects, functions, and instances.

  ```typescript
  // bad
  var OBJEcttsssss = {};
  var this_is_my_object = {};
  function c() {}
  var u = new user({
    name: 'Bob Parr'
  });

  // good
  var thisIsMyObject = {};
  function thisIsMyFunction() {}
  var user = new User({
    name: 'Bob Parr'
  });
  ```

- Use PascalCase when naming classes.

  ```typescript
  // bad
  class user {
    name: string;
    constructor(options: object){
      this.name = options.name;
    }
  }

  var bad = new user({
    name: 'nope'
  });

  // good
  class User {
    name: string;
    constructor(options: object){
      this.name = options.name;
    }
  }

  var good = new User({
    name: 'yup'
  });
  ```

- There is no need to save a reference to `this`. Just use a fat arrow function.

  ```typescript
  // bad
  function() {
    var self = this;
    return function() {
      console.log(self);
    };
  }

  // good
  function() {
    return () => {
      console.log(this);
    };
  }
  ```

- Name your functions. This is helpful for stack traces.

  ```typescript
  // bad
  var log = function(msg) {
    console.log(msg);
  };

  // good
  var log = function log(msg) {
    console.log(msg);
  };
  ```

- **Note:** IE8 and below exhibit some quirks with named function expressions.  See [http://kangax.github.io/nfe/](http://kangax.github.io/nfe/) for more info.

- If your file exports a single class, your filename should be exactly the name of the class.
  ```typescript
  // file contents
  class CheckBox {
    // ...
  }
  module.exports = CheckBox;

  // in some other file
  // bad
  var CheckBox = require('./checkBox');

  // bad
  var CheckBox = require('./check_box');

  // good
  var CheckBox = require('./CheckBox');
  ```

**[⬆ back to top](#table-of-contents)**


## Accessors

- Accessor functions for properties are not required.
- If you do make accessor functions use getVal() and setVal('hello').

  ```typescript
  // bad
  dragon.age();

  // good
  dragon.getAge();

  // bad
  dragon.age(25);

  // good
  dragon.setAge(25);
  ```

- If the property is a boolean, use isVal() or hasVal().

  ```typescript
  // bad
  if (!dragon.age()) {
    return false;
  }

  // good
  if (!dragon.hasAge()) {
    return false;
  }
  ```

- It's okay to create get() and set() functions, but be consistent.

  ```typescript
  function Jedi(options) {
    options || (options = {});
    var lightsaber = options.lightsaber || 'blue';
    this.set('lightsaber', lightsaber);
  }

  Jedi.prototype.set = function(key, val) {
    this[key] = val;
  };

  Jedi.prototype.get = function(key) {
    return this[key];
  };
  ```

**[⬆ back to top](#table-of-contents)**

## Class

### Class members

- Public instance variables do not need a `public` declaration. Each member is `public` by default.
```typescript
// bad
public name: string;

// good
name: string;

Private instance variables do need a private declaration.

// bad
location: string;

// good
private location name: string;

By default don't use a leading underscore _ to name private members

// bad
private _firstName = 'Panda';

// good
private firstName = 'Panda';

Use a leading underscore _ to name a private member, if this member is needed by same named getter / setter method

// good
class Person {
    private _name: string = null;

    get name (): string {
        return this._name;
    }

    set name (value: string): void {
     this._name = value;
    }
}

As a shorthand any class member (private or public) can be created and initialized by using constructor parameters.

// bad
class Person {  
    name:string;        
    constructor(name: string) {
          this.name = name;
    }
}

// good
class Person {
    constructor(public name: string) {

    }
}

Events

When attaching data payloads to events (whether DOM events or something more proprietary like Backbone events), pass a hash instead of a raw value. This allows a subsequent contributor to add more data to the event payload without finding and updating every handler for the event. For example, instead of:

// bad
$(this).trigger('listingUpdated', listing.id);

...

$(this).on('listingUpdated', function(e, listingId) {
  // do something with listingId
});

prefer:

// good
$(this).trigger('listingUpdated', { listingId : listing.id });

...

$(this).on('listingUpdated', function(e, data) {
  // do something with data.listingId
});

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Modules

When using modules (and we can not encourage you enough to do so) make sure to use the ES6 module definition (not the TypeScript own modules)

// bad
module Validation {
    export interface doSomething {
        isAcceptable(s: string): boolean;
    }
}

// good
export default function doSomething () {

};

The module export definition should be the last statement(s) within the file:

// bad
import { Foo } from './Foo';

class Car {

}

export default Car;

let foo: string = 'bar'

// good
import { Foo } from './Foo';

class Car {

}

export default Car;

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jQuery

Prefix jQuery object variables with a $.

// bad
var sidebar = $('.sidebar');

// good
var $sidebar = $('.sidebar');

Cache jQuery lookups.

// bad
function setSidebar() {
  $('.sidebar').hide();

  // ...stuff...

  $('.sidebar').css({
    'background-color': 'pink'
  });
}

// good
function setSidebar() {
  var $sidebar = $('.sidebar');
  $sidebar.hide();

  // ...stuff...

  $sidebar.css({
    'background-color': 'pink'
  });
}

For DOM queries use Cascading $('.sidebar ul') or parent > child $('.sidebar > ul'). jsPerf

Use find with scoped jQuery object queries.

// bad
$('ul', '.sidebar').hide();

// bad
$('.sidebar').find('ul').hide();

// good
$('.sidebar ul').hide();

// good
$('.sidebar > ul').hide();

// good
$sidebar.find('ul').hide();

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ECMAScript 5 Compatibility

Refer to Kangax's ES5 compatibility table.

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Testing

Yup.
```
function() {
  return true;
}
```

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Performance

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Resources

Read This

Annotated ECMAScript 5.1

Tools

Code Style Linters
- JSHint - Airbnb Style .jshintrc
- JSCS - Airbnb Style Preset

Other Styleguides

Other Styles

Naming this in nested functions - Christian Johansen
Conditional Callbacks - Ross Allen
Popular JavaScript Coding Conventions on Github - JeongHoon Byun
Multiple var statements in JavaScript, not superfluous - Ben Alman

Further Reading

Understanding JavaScript Closures - Angus Croll
Basic JavaScript for the impatient programmer - Dr. Axel Rauschmayer
You Might Not Need jQuery - Zack Bloom & Adam Schwartz
ES6 Features - Luke Hoban
Frontend Guidelines - Benjamin De Cock

Books

JavaScript: The Good Parts - Douglas Crockford
JavaScript Patterns - Stoyan Stefanov
Pro JavaScript Design Patterns - Ross Harmes and Dustin Diaz
High Performance Web Sites: Essential Knowledge for Front-End Engineers - Steve Souders
Maintainable JavaScript - Nicholas C. Zakas
JavaScript Web Applications - Alex MacCaw
Pro JavaScript Techniques - John Resig
Smashing Node.js: JavaScript Everywhere - Guillermo Rauch
Secrets of the JavaScript Ninja - John Resig and Bear Bibeault
Human JavaScript - Henrik Joreteg
Superhero.js - Kim Joar Bekkelund, Mads Mobæk, & Olav Bjorkoy
JSBooks - Julien Bouquillon
Third Party JavaScript - Ben Vinegar and Anton Kovalyov
Effective JavaScript: 68 Specific Ways to Harness the Power of JavaScript - David Herman
Eloquent JavaScript - Marijn Haverbeke
You Don't Know JS - Kyle Simpson

Blogs

Podcasts

JavaScript Jabber

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In the Wild

This is a list of organizations that are using this style guide. Send us a pull request or open an issue and we'll add you to the list.

Aan Zee: AanZee/javascript
Adult Swim: adult-swim/javascript
Airbnb: airbnb/javascript
American Insitutes for Research: AIRAST/javascript
Apartmint: apartmint/javascript
Avalara: avalara/javascript
Compass Learning: compasslearning/javascript-style-guide
DailyMotion: dailymotion/javascript
Digitpaint digitpaint/javascript
Evernote: evernote/javascript-style-guide
ExactTarget: ExactTarget/javascript
Gawker Media: gawkermedia/javascript
GeneralElectric: GeneralElectric/javascript
GoodData: gooddata/gdc-js-style
Grooveshark: grooveshark/javascript
How About We: howaboutwe/javascript
InfoJobs: InfoJobs/JavaScript-Style-Guide
Intent Media: intentmedia/javascript
Jam3: Jam3/Javascript-Code-Conventions
Kinetica Solutions: kinetica/javascript
Mighty Spring: mightyspring/javascript
MinnPost: MinnPost/javascript
ModCloth: modcloth/javascript
Money Advice Service: moneyadviceservice/javascript
Muber: muber/javascript
National Geographic: natgeo/javascript
National Park Service: nationalparkservice/javascript
Nimbl3: nimbl3/javascript
Nordic Venture Family: CodeDistillery/javascript
Orion Health: orionhealth/javascript
Peerby: Peerby/javascript
Razorfish: razorfish/javascript-style-guide
reddit: reddit/styleguide/javascript
REI: reidev/js-style-guide
Ripple: ripple/javascript-style-guide
SeekingAlpha: seekingalpha/javascript-style-guide
Shutterfly: shutterfly/javascript
StudentSphere: studentsphere/javascript
Target: target/javascript
TheLadders: TheLadders/javascript
T4R Technology: T4R-Technology/javascript
Userify: userify/javascript
VoxFeed: VoxFeed/javascript-style-guide
Weggo: Weggo/javascript
Zillow: zillow/javascript
ZocDoc: ZocDoc/javascript

Translation

This style guide is also available in other languages:

Brazilian Portuguese: armoucar/javascript-style-guide
Bulgarian: borislavvv/javascript
Catalan: fpmweb/javascript-style-guide
Chinese(Traditional): jigsawye/javascript
Chinese(Simplified): adamlu/javascript-style-guide
French: nmussy/javascript-style-guide
German: timofurrer/javascript-style-guide
Japanese: mitsuruog/javacript-style-guide
Korean: tipjs/javascript-style-guide
Polish: mjurczyk/javascript
Russian: uprock/javascript
Spanish: paolocarrasco/javascript-style-guide
Thai: lvarayut/javascript-style-guide

The JavaScript Style Guide Guide

Reference

Chat With Us About JavaScript

Find us on gitter.

Contributors

View Contributors

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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Airbnb JavaScript TypeScript Style Guide(unofficial) {

Table of Contents

Types

Objects

Arrays

Strings

Functions

Properties

Variables

Hoisting

Comparison Operators & Equality

Blocks

Comments

Events

Modules

jQuery

ECMAScript 5 Compatibility

Testing

Performance

Resources

In the Wild

Translation

The JavaScript Style Guide Guide

Chat With Us About JavaScript

Contributors

License

};

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Contributors 92

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furny/ts-styleguide

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Repository files navigation

Airbnb JavaScript TypeScript Style Guide(unofficial) {

Table of Contents

Types

Objects

Arrays

Strings

Functions

Properties

Variables

Hoisting

Comparison Operators & Equality

Blocks

Comments

Events

Modules

jQuery

ECMAScript 5 Compatibility

Testing

Performance

Resources

In the Wild

Translation

The JavaScript Style Guide Guide

Chat With Us About JavaScript

Contributors

License

};

About

Resources

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Forks

Releases

Packages 0

Contributors 92

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Packages