Top 1K Features Creators Events Podcasts Books Extensions Interviews Blog Explorer CSV

TypeScript

< >
home LEET SHEET terminal newspaper edit

TypeScript is an open source programming language created in 2012 by Anders Hejlsberg.

#14on PLDB 12Years Old 3mRepos
Download source code:
git clone https://github.com/microsoft/TypeScript
Homepage · Leet Sheet · REPL · Try It Online · Download · Source Code · Blog · Wikipedia · Subreddit · Twitter · Release Notes · Docs

TypeScript is a free and open-source programming language developed and maintained by Microsoft. It is a strict syntactical superset of JavaScript, and adds optional static typing to the language. Anders Hejlsberg, lead architect of C# and creator of Delphi and Turbo Pascal, has worked on the development of TypeScript. Read more on Wikipedia...


Example from Riju:
console.log("Hello, world!");
Example from hello-world:
console.log("Hello World");
Example from the Hello World Collection:
// Hello world in TypeScript alert('Hello world!');
Example from Linguist:
console.log("Hello, World!");
Example from Wikipedia:
class Person { private name: string; private age: number; private salary: number; constructor(name: string, age: number, salary: number) { this.name = name; this.age = age; this.salary = salary; } toString(): string { return `${this.name} (${this.age}) (${this.salary})`; // As of version 1.4 } }

Language features

Feature Supported Example Token
Standard Library ✓ console.log("Hello, World!");
Type Aliases ✓ type Second = number;
hasGradualTypes ✓
MultiLine Comments ✓ /* A comment */ /* */
Comments ✓ // A comment
Algebraic Data Type ✓ declare type numOrString = string | number
Line Comments ✓ // A comment //
Union Types ✓ declare type numOrString = string | number
Single-Type Arrays ✓ const scores: int[]
Type Inference ✓
Strings ✓ "hello world" "
Type Parameters ✓ function identity(arg: T): T { return arg; }
Static Typing ✓
Inheritance ✓ class B {} class A extends B {}
Print() Debugging ✓ console.log("Hi") console.log
Namespaces ✓ // Typescript even supports splitting namespaces across multiple files: // Validation.ts namespace Validation { export interface StringValidator { isAcceptable(s: string): boolean; } } // LettersOnlyValidator.ts /// namespace Validation { const lettersRegexp = /^[A-Za-z]+$/; export class LettersOnlyValidator implements StringValidator { isAcceptable(s: string) { return lettersRegexp.test(s); } } }
Mixins ✓ // https://www.typescriptlang.org/docs/handbook/mixins.html class SmartObject implements Disposable, Activatable { } // Note: still need to do some runtime ops to make that work.
Interfaces ✓ // https://www.typescriptlang.org/docs/handbook/interfaces.html interface SquareConfig { color?: string; width?: number; }
File Imports ✓ import { ZipCodeValidator } from "./ZipCodeValidator"; /// /// import moo = module('moo'); ///
Type Casting ✓ something;
Classes ✓ class Person {}
Booleans ✓ const result = true
Generics ✓ function identity(arg: T): T { return arg; }
Abstract Types ✓ abstract class Animal {} class Dog extends Animal
Access Modifiers ✓ class Person { private _age = 2 public get age() { return _age } protected year = 1990 }
Static Methods ✓ class Person { static sayHi() { console.log("Hello world") } }
Enums ✓ enum Direction { Up, Down }
Case Insensitive Identifiers X
Semantic Indentation X
Operator Overloading X

- Build the next great programming language · Add · About · Search · Keywords · Livestreams · Labs · Resources · Acknowledgements

Built with Scroll v144.0.0