typescript
Advanced tools
Package description
The TypeScript npm package is a superset of JavaScript that compiles to clean JavaScript output. It adds optional static typing to JavaScript, which can help with the development of large-scale applications and lead to more robust code. TypeScript is designed for the development of large applications and transcompiles to JavaScript.
Static Type Checking
TypeScript allows you to define types for your variables and function parameters, which helps catch errors at compile time rather than at runtime.
let isDone: boolean = false;Classes and Interfaces
TypeScript supports modern JavaScript features like classes and interfaces, allowing for more structured and maintainable code.
class Animal {
name: string;
constructor(theName: string) { this.name = theName; }
move(distanceInMeters: number = 0) {
console.log(`${this.name} moved ${distanceInMeters}m.`);
}
}Modules
TypeScript provides support for modules, enabling you to organize your code into separate files and manage dependencies more effectively.
import { ZipCodeValidator } from './ZipCodeValidator';
let myValidator = new ZipCodeValidator();Generics
Generics enable you to create reusable components that work with a variety of types rather than a single one.
function identity<T>(arg: T): T {
return arg;
}Advanced Types
TypeScript offers advanced types like intersection types, union types, and mapped types, which provide powerful ways to work with your data structures.
type Tree<T> = {
value: T;
left: Tree<T>;
right: Tree<T>;
};Tooling Support
TypeScript integrates with many editors and provides features like autocompletion, type checking, and source navigation, enhancing the development experience.
n/aFlow is a static type checker for JavaScript. It provides similar functionality to TypeScript, offering static typing in JavaScript, but it uses a different syntax and type system.
Babel preset for TypeScript allows Babel to parse and transpile TypeScript code. While Babel itself is mainly a JavaScript compiler, this preset brings TypeScript support to Babel's ecosystem.
CoffeeScript is a language that compiles into JavaScript. It provides syntactic sugar inspired by Ruby, Python, and Haskell to enhance JavaScript readability and brevity. It does not offer static typing but focuses on cleaner syntax.
Elm is a functional language that compiles to JavaScript. It emphasizes simplicity and quality tooling, and while it is not a direct alternative to TypeScript's type system, it offers strong typing and eliminates runtime exceptions.
Dart is an object-oriented, class-defined, garbage-collected language using a C-style syntax that transcompiles optionally into JavaScript. It includes static typing and is developed by Google, often used for building web and mobile applications.
Readme
TypeScript is a language for application-scale JavaScript. TypeScript adds optional types, classes, and modules to JavaScript. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the playground, and stay up to date via our blog and twitter account.
There are many ways to contribute to TypeScript.
In order to build the TypeScript compiler, ensure that you have Git and Node.js installed.
Clone a copy of the repo:
git clone https://github.com/Microsoft/TypeScript.git
Change to the TypeScript directory:
cd TypeScript
Install Jake tools and dev dependencies:
npm install -g jake
npm install
Use one of the following to build and test:
jake local # Build the compiler into built/local
jake clean # Delete the built compiler
jake LKG # Replace the last known good with the built one.
# Bootstrapping step to be executed when the built compiler reaches a stable state.
jake tests # Build the test infrastructure using the built compiler.
jake runtests # Run tests using the built compiler and test infrastructure.
# You can override the host or specify a test for this command.
# Use host=<hostName> or tests=<testPath>.
jake runtests-browser # Runs the tests using the built run.js file. Syntax is jake runtests. Optional
parameters 'host=', 'tests=[regex], reporter=[list|spec|json|<more>]'.
jake baseline-accept # This replaces the baseline test results with the results obtained from jake runtests.
jake -T # List the above commands.
node built/local/tsc.js hello.ts
For details on our planned features and future direction please refer to our roadmap.
FAQs
TypeScript is a language for application scale JavaScript development
We found that typescript demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 8 open source maintainers collaborating on the project.
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