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Comment in C++

1. What is Comment in C++?​

  • A comment in C++ is a programmer-readable note that is inserted directly into the source code of a program.
  • Comments are ignored by the compiler and are meant for the programmer’s use only.
  • They serve as a form of in-code documentation, helping developers understand the purpose, logic, or explanation behind specific code lines

2. Why do we use comments in C++?​

Comments serve several purposes:

  • Explanation: They explain the code, making it more readable and understandable for other programmers.
  • Debugging: Comments can be useful for debugging by providing context or temporarily disabling code segments.
  • Documentation: They document algorithms, variable purposes, or clarify unclear code segments.
  • Collaboration: Comments help other developers understand your code when collaborating on projects.

comment-in-cpp

3. Write a simple program to demonstrate the use of comments in C++.​

#include <iostream>
using namespace std;

int main() {
    // This is a single-line comment
    cout << "Hello, World!"; // Another single-line comment
    return 0;
}

In this program, we use both single-line comments (//) to explain the code and prevent execution of those comment lines

4. Types of comments in C++​

i. Single Line Comment

  • Starts with // and applies to a single line only.
  • Compiler ignores any text after //.
  • Used for brief explanations or annotations within a line of code. Example:
int age = 25; // Stores the user's age

ii. Multi Line Comment

  • Starts with /* and ends with */.
  • Can span multiple lines but cannot be nested.
  • Any text between /* and */ is ignored by the compiler.
  • Used for longer descriptions, explaining complex logic or function purposes. Example:
/*
* This function calculates the area of a rectangle
* given its length and width.
*/
int calculateArea(int length, int width) {
  // ... function implementation
}

iii. Documentation Comment

  • Used for documenting functions, classes, and their parameters.
  • Typically starts with /** and ends with */.
  • Contains additional information for tools like Doxygen.
  • Example (not standard C++):
/**
 * @param x integer value to add
 * @param y integer value to add
	@@ -66,3 +75,4 @@ int add(int x, int y) {
}

By effectively using comments, you can improve the understandability and maintainability of your C++ programs, both for yourself and others who may read your code in the future.