array

array

A better array for the browser and node.js. Supports events & many functional goodies.

The functional bits are based off the Enumerable component.

Installation

Node.js

npm install array

Browser with component

component install matthewmueller/array

Browser (standalone, amd, etc.)

• Development (24k): dist/array.js
• Production (4k w/ gzip): dist/array.js

Note: if you use this library standalone, array will be attached to the window. You can access it with window.array() or just array(). Keep in mind javascript is case-sensitive and Array() will create a native array.

Examples

Iteration:

users
  .map('friends')
  .select('age > 20 && age < 30')
  .map('name.first')
  .select(/^T/)

fruits.find({ name : 'apple' }).color

users.sort('name.last', 'descending')

Events:

var array = require('array'),
    users = array();

users.on('add', function(user) {
  console.log('added', user);
});

users.on('remove', function(user) {
  console.log('removed', user);
});

users.push(user);
users.splice(0, 3, user);

Design

This library uses an array-like object to implement all its methods. This is very similar to how jQuery lets you do: $('.modal')[0] and $('p').length.

This library differs from component/enumerable in that it has events and does not wrap the array. To access the actual array in component/enumerable you have to call .value(). For the most part, you can treat array just like a real array, because it implements all the same methods.

Caveats

When working with array it's important to keep in mind that array is not an actual Array, but an array-like object. There are a few caveats that come with this data type:

• you cannot manually set array indexes because the length value will not be updated. You will have to use the mutator methods provided like push, pop, etc.
• arr instanceof Array will return false. arr instanceof Object will return true. So there may be some interoperability issues if you try to blindly pass these arrays through other libraries.

Keep in mind both these issues are also present when working with jQuery objects as well as Backbone Collections.

Events

• add (item) - emitted when items are added to the array (push, unshift, splice)
• remove (item) - emitted when items are removed from the array (pop, shift, splice)

An event will be emitted for each item you add or remove. So if you do something like:

fruits.on('add', function(item) {});
fruits.push('apple', 'orange', 'pear')

The add event will be fired 3 times with the item being "apple", "orange", and "pear" respectively.

API

array(mixed)

Initialize an array.

As an empty array:

var arr = array();

As an array with values:

var arr = array([1, 2, 3, 4]);

Or as a mixin:

function Notes() {}
array(Notes.prototype);

Array methods

array implements all the same methods as a native array. For more information, visit MDN.

Mutators:

Mutator methods that modify the array will emit "add" and "remove" events.

• pop(): Removes the last element from an array and returns that element.
• push(item, ...): Adds one or more elements to the end of an array and returns the new length of the array.
• reverse(): Reverses the order of the elements of an array -- the first becomes the last, and the last becomes the first.
• shift(): Removes the first element from an array and returns that element.
• splice(i, k, [item, ...]): Adds and/or removes elements from an array.
• unshift(item, ...): Adds one or more elements to the front of an array and returns the new length of the array.

Accessors:

• concat(arr): Returns a new array comprised of this array joined with other array(s) and/or value(s).
• join(str): Joins all elements of an array into a string.
• slice(i, k): Extracts a section of an array and returns a new array.
• toString(): Returns a string representing the array and its elements. Overrides the Object.prototype.toString method.
• lastIndexOf(item): Returns the last (greatest) index of an element within the array equal to the specified value, or -1 if none is found.

Iteration Methods:

array implements most of the methods of component/enumerable. The documentation below was originally written by visionmedia.

.each(fn)

Iterate each value and invoke fn(val, i).

users.each(function(val, i){})

.map(fn|str)

Map each return value from fn(val, i).

Passing a callback function:

users.map(function(user){
  return user.name.first
})

Passing a property string:

users.map('name.first')

.select(fn|str)

Select all values that return a truthy value of fn(val, i). The argument passed in can either be a function or a string.

users.select(function(user){
  return user.age > 20
})

With a property:

items.select('complete')

With a condition:

users.select('age > 20')

.unique(fn|str)

Select all unique values.

nums.unique()

users.unique('age')

.reject(fn|str|mixed)

Reject all values that return a truthy value of fn(val, i).

Rejecting using a callback:

users.reject(function(user){
  return user.age < 20
})

Rejecting with a property:

items.reject('complete')

Rejecting values via ==:

data.reject(null)
users.reject(toni)

.sort([str|fn], [direction])

Sorts the array

Basic sort:

prices.sort()

Sort by the created key in ascending order. the following are equivalent:

users.sort('created')
users.sort('created', 'ascending')
users.sort('created', 'asc')
users.sort('created', 1)
users.sort('created', true)

Sort in descending order. The following are equivalent:

food.sort('calories', 'descending')
food.sort('calories', 'desc')
food.sort('calories', -1)
food.sort('calories', false)

Using a function:

users.sort(function(user1, user2) {})

.compact()

Reject null and undefined.

[1, null, 5, undefined].compact()
// => [1,5]

.find(fn)

Return the first value when fn(val, i) is truthy, otherwise return undefined.

users.find(function(user){
  return user.role == 'admin'
})

.findLast(fn)

Return the last value when fn(val, i) is truthy, otherwise return undefined.

users.findLast(function(user){
  return user.role == 'admin'
})

.none(fn|str)

Assert that none of the invocations of fn(val, i) are truthy.

For example ensuring that no pets are admins:

pets.none(function(p){ return p.admin })
pets.none('admin')

.any(fn)

Assert that at least one invocation of fn(val, i) is truthy.

For example checking to see if any pets are ferrets:

pets.any(function(pet){
  return pet.species == 'ferret'
})

.count(fn)

Count the number of times fn(val, i) returns true.

var n = pets.count(function(pet){
  return pet.species == 'ferret'
})

.indexOf(mixed)

Determine the indexof mixed or return -1.

.has(mixed)

Check if mixed is present in this enumerable.

.reduce(fn, mixed)

Reduce with fn(accumulator, val, i) using optional init value defaulting to the first enumerable value.

.max(fn|str)

Determine the max value.

With a callback function:

pets.max(function(pet){
  return pet.age
})

With property strings:

pets.max('age')

With immediate values:

nums.max()

.sum(fn|str)

Determine the sum.

With a callback function:

pets.sum(function(pet){
  return pet.age
})

With property strings:

pets.sum('age')

With immediate values:

nums.sum()

.first([mixed])

Return the first value, or first n values. If you pass in an object or a function, first will call find.

.last([mixed])

Return the last value, or last n values. If you pass in an object or function, last will call findLast.

.hash(key)

Create a hash from the given key.

var fruits = array();
fruits.push({ name : "apple", color : "red" });
fruits.push({ name : "pear", color : "green" });
fruits.push({ name : "orange", color : "orange" });

var obj = fruits.hash('name');
obj.apple //=> { name : "apple", color : "red" }
obj.pear //=> { name : "pear", color : "green" }
obj.orange //=> { name : "orange", color : "orange" }

toJSON()

Return an array. If array contains objects that implement ,toJSON(), array.js will call obj.toJSON() on each item. Otherwise return the contents.

toArray()

Returns an native array.

Benchmarks

Benchmarks are preliminary but also promising:

• native vs. array.js vs underscore.js: http://jsperf.com/native-vs-array-js-vs-underscore

Run tests

npm install .
npm test

License

(The MIT License)

Copyright (c) 2013 Matt Mueller [e-mail]

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.