TypeScript — Hello World
The classic hello-world in TypeScript (shipped as .mts to avoid the MPEG-TS .ts collision) — a typed function for testing TypeScript-aware highlighters and the tsc compiler.
// The classic first program, in TypeScript.
function greet(name: string): string {
return `Hello, ${name}!`;
}
console.log(greet("world"));
Specifications
- Language
- TypeScript
- Kind
- hello-world
- Lines
- 6
- Encoding
- UTF-8
- Line Endings
- LF
What is a .mts file?
TypeScript (.mts) is a plain-text source file for TypeScript — a statically typed superset of JavaScript that compiles to plain JS. The .mts extension specifically marks an ES-module TypeScript file. It adds interfaces, generics, enums, and type annotations on top of JavaScript syntax.
How to use this file
Use an example .mts file to test TypeScript-aware highlighters, the tsc compiler and type checker, ESLint with the TS parser, and editor tooling. (We ship TypeScript as .mts to avoid the MPEG-TS .ts extension collision.)
Related files
- mtsTypeScript — Shapes (union, generics, enum)A realistic TypeScript snippet with an enum, a discriminated union, generics, exhaustive switch handling, and a typed reduce — for testing the type checker, highlighters, and the TS ESLint parser.
- cC — Hello WorldThe classic hello-world in C — an include, main, and printf — for testing highlighters, C compilers, and parsers against the canonical first program.
- cC — Linked list (structs, malloc, pointers)A realistic C program: a singly linked list with a typedef struct, malloc/free memory management, pointer walking, and error handling — for testing highlighters, compilers, and static analysers.
- cppC++ — Hello WorldThe classic hello-world in C++ — iostream and std::cout — for testing highlighters, C++ compilers, and parsers.
- cppC++ — Series (class template, STL)A realistic C++ snippet with a class template, STL algorithms (max_element, accumulate), std::move, and range handling — for testing highlighters, g++/clang++, and parsers against real templates.
- cssCSS — Component styles (variables, flexbox, keyframes)A realistic component stylesheet using custom properties, flexbox, a fluid clamp() font size, color-mix(), a keyframe animation, and a media query — for testing CSS parsers, linters (stylelint), and highlighters.
Generated by generation/code_samples.py. Free for any use, no attribution required — license.