Comments in C++

Comments can be used to explain C++ code, and to make it more readable. It can also be used to prevent execution when testing alternative code. Comments can be singled-lined or multi-lined.

Single-line comments start with two forward slashes (//).

Any text between // and the end of the line is ignored by the compiler (will not be executed).

This example uses a single-line comment before a line of code:

Example

// This is a comment
cout << "Hello World!";

This example uses a single-line comment at the end of a line of code:

Example

cout << "Hello World!"; // This is a comment

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C++ Multi-line Comments

Multi-line comments start with /* and ends with */.

Any text between /* and */ will be ignored by the compiler:

Example

/* The code below will print the words Hello World!
to the screen, and it is amazing */
cout << "Hello World!";

Single or multi-line comments?

It is up to you which you want to use. Normally, we use // for short comments, and /* */ for longer.