[](https://coveralls.io/github/ENikS/LINQ?branch=master)
[](https://dependencyci.com/github/ENikS/LINQ)
[](https://github.com/ENikS/LINQ/blob/master/LICENSE)
## Language-Integrated Query (LINQ)
**linq-es2015** is a complete implementation of [LINQ (Language-Integrated Query)](https://en.wikipedia.org/wiki/Language_Integrated_Query) pattern and enables you to express traversal, filter, and projection operations over data in JavaScript or any related programming languages (TypeScript, CoffeeScript, etc).
It provides an implementation of the standard query operators for querying any data source that implements Iterable. Methods that are used in a query that return a sequence of values do not consume the target data until the query object is enumerated. This is known as [deferred execution](https://blogs.msdn.microsoft.com/charlie/2007/12/10/linq-and-deferred-execution/). Methods that are used in a query that returns a singleton value execute and consume the target data immediately.
The library is a continuous effort to implement LINQ using latest features of TypeScript and JavaScript languages (For [ES5](http://www.ecma-international.org/ecma-262/5.1/) compatible library look at [linq-es5](https://github.com/ENikS/LINQ/tree/linq-es5) branch and corresponding [NPM package](https://www.npmjs.com/package/linq-es5)). The library is implemented in TypeScript and transpiled into JavaScript. It is distributed as a native node module.
Browserified and minified standalone UMD modules are located in ./dist directory and could be used directly in compatible browsers.
This library uses latest [ECMAScript 2015](http://www.ecma-international.org/ecma-262/6.0/) language specification and utilizes [Iterables](http://www.ecma-international.org/ecma-262/6.0/#sec-iterable-interface): ([ [System.iterator] ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols)), JavaScript generators ([function*](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*)), and [for of](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of) loops. All relevant methods are implemented with [deferred execution](https://blogs.msdn.microsoft.com/charlie/2007/12/10/linq-and-deferred-execution/) so no unnecessary iterations are performed.
The code is backwards compatible with [linq-es5](https://github.com/ENikS/LINQ/tree/linq-es5) and [C#](https://msdn.microsoft.com/en-us/library/system.linq.enumerable.aspx) implementations.
## Installation
```
npm install linq-es2015
```
## Using
```javascript
var Enumerable = require("linq-es2015");
var count = Enumerable.asEnumerable( [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] )
.Where(a => a % 2 == 1)
.Count()
```
For live examples please follow links to ([Node](https://tonicdev.com/eniks/using-linq)) or ([Browser](https://jsfiddle.net/ENikS/pyvjcfa0)).
## Using in browser
[Browserified](//browserify.org/) [standalone](//github.com/substack/node-browserify#usage) [UMD](//github.com/umdjs/umd) module is located in ./dist directory and could be accessed through [NPM CDN service](//unpkg.com). Both [linq.js](//unpkg.com/linq-es2015/dist/linq.js) and [linq.min.js](//unpkg.com/linq-es2015/dist/linq.min.js) are available.
[[See Example](//jsfiddle.net/ENikS/pyvjcfa0/)]
## Using in Angular
The same package could be used on a server as well as on the client. The package does not require any special handling and used as any other module.
[[See Example](https://github.com/ENikS/LINQ/tree/examples/Angular)]
## Naming Convention
When library is used in TypeScript method names follow original C# convention (Name starts with capital letter). It is done for compatibility reasons so that code could be cut/pasted from C# with just minor reformatting.
If used directly in JavaScript names follow [camelCase](https://en.wikipedia.org/wiki/CamelCase) notation.
## Documentation
* [Library Reference](https://github.com/ENikS/LINQ/wiki)
* [LINQ (Language-Integrated Query)](https://msdn.microsoft.com/en-us/library/bb397926.aspx)
* [Original Documentation (C#)](https://msdn.microsoft.com/en-us/library/system.linq.enumerable.aspx)
## Example Projects
* [Browser Example](https://jsfiddle.net/ENikS/pyvjcfa0/)
* [Node Example](https://tonicdev.com/eniks/using-linq)
* [Angular 2 Example](https://github.com/ENikS/LINQ/tree/examples/Angular)
* [Node Console Example](https://github.com/ENikS/LINQ/tree/examples/Node)
* [TypeScript/JavaScript Web Example](https://github.com/ENikS/LINQ/tree/examples/TypeScript)