We all know that every ‘,’ matters in this language, so I decided to talk directly about that character today. So, how much impact can be for such a small little character?

It’s just ‘,’ – The Comma Operator

by Coral Kashri

From the article:

This operator comes from C, where it tells the compiler to evaluate all the expressions (left to right) and to return the result of the latest evaluated expression. For example:

     int a, b;

     a = 5, b = 4, b += a, ++a, std::cout << b << " " << a; // Prints 9 6

Another example of that operator usage is as follows:

     for (size_t i = 0, k = 500; i < 10; ++i, ++k) { /*...*/ }

We can see this operator in action in the third section of the for statement. It evaluates the ++i and then evaluates ++k.