How are comments written in C++ code?

In C++, comments are written using two primary formats: single-line comments and multi-line comments. Single-line comments begin with // and continue until the end of that line, making it easy to add brief notes without disrupting the flow of the code. Multi-line comments are enclosed between /* and */, allowing for longer descriptions or notes that may span multiple lines.

This method of commenting is essential for code documentation, as it provides clarity for anyone reading the code later, whether that be the original author or someone else. By utilizing both single-line and multi-line comments effectively, programmers can improve the readability and maintainability of their code.

Understanding the correct syntax to avoid syntax errors is crucial; for example, failing to close a multi-line comment with */ could lead to compilation errors. Other options presented have incorrect comment syntax as per the C++ standards, such as using # or --, which do not serve the purpose of commenting in C++.