C++ · Chapter 6 of 49
C++ Comments
Comments are notes in the source code that the compiler ignores. C++ supports single-line comments starting with `//` and multi-line comments wrapped in `/* ... */`.
Good comments explain *why* something is done, not just *what* the code does, since the code itself already shows the 'what'.
Single-line comments
Anything after `//` on a line is ignored by the compiler. These are great for short notes next to a line of code.
Multi-line comments
`/* ... */` can span several lines and is often used for file headers, licence notices, or temporarily disabling a block of code.
Example 1 (cpp)
// This prints a greeting
std::cout << "Hi";Output
HiThe // comment is ignored during compilation.
Example 2 (cpp)
/* This is a
multi-line comment */
std::cout << "Done";Output
DoneEverything between /* and */ is ignored, even across lines.
Key points
- // starts a single-line comment.
- /* */ wraps a multi-line comment.
- Comments are ignored by the compiler.
- Use comments to explain intent, not obvious syntax.
💡 Note: Overusing comments to restate obvious code is a code smell — let clear variable names do the talking.