Question

how to add comment line in C++ program​

Answer 1

Answer:

Comments are portions of the code ignored by the compiler which allow the user to make simple notes in the relevant areas of the source code. Comments come either in block form or as single lines.

1. Single-line comments (informally, C++ style), start with // and continue until the end of the line. If the last character in a comment line is a \ the comment will continue in the next line.
2. Multi-line comments (informally, C style), start with /* and end with */.