A .tsx file is usually a TypeScript file that includes JSX, so it’s commonly used for React components. In a TSX file, you comment out a line the same way you do in JavaScript/TypeScript: use // for a single line, or /* ... */ for multiple lines.

TSX basics

  • Use .tsx when the file contains React/JSX markup.
  • Use .ts when the file is plain TypeScript with no JSX.

Commenting a line

  • Single line: // this is a comment
  • Block comment: /* this is a comment */

Example:

tsx

// This button renders the form
const Button = () => {
  return <button>Click me</button>;
};

Practical note

If you’re editing a React component, .tsx is the right file type because it lets TypeScript understand JSX syntax. That’s the main difference people run into when moving between .ts and .tsx.

TL;DR: .tsx is for TypeScript + JSX, and you comment lines with //.