Learn how to use Comments and why you should always use them

Single Line Comment

In C++, a single comment begins with a double slash (//) and continue till the ends of the line

//This is a comment
int my_number = 128; //This is another comment							the comment continue here and forever

Multi-Lines Comment

First thing to know is that a multi-lines comment does not necessary have multiple lines. The  name simply refers to the fact that you can comment multiple lines with it if you want.

In C++, a multi-lines comment begins with a slash-asterisk (/*) and ends with a asterisk-slash (*/), The multi-lines comment can be used anywhere in the code, I really mean any where, even between a variable type and its name when declaring it.

	This is a multi-lines comment
	Line 1
	Line N
/* this comment is only one line, it does not continue forever, it ends with the asterisk-slash */ int my_number = 128;
std::string /*this is a comment*/ my_string = "hello everyone";

Why Comments Are Important

Comments are useful but also very important and you should learn to use them instinctively every time. Comments are not part of your program, if you take a program with some comments and remove them all, your program will still work the same. So why do we use them ?

Because they allows you do describe what your program is doing at any moment in a very human friendly way. Also If you are working with other peoples you want them to know what your code is doing just by reading it. Even if you work alone, it may happen that you stop working on your code for several months, without comments you will have an hard time understating your own code when come back to it.

As you can see with the examples below, code with comments are more easy to understand.

//Example 1 : without comment
float surf(float w, float h)
	return w * h;
//Example 2 : with comments
	The surf function computes the surface of any rectangulare shape given its width and its height
	w = width
	h = height
float surf(float w, float h)
	return w * h;	//return surface