Different behaviour of comma operator in C++ with return?

Question

This (note the comma operator):

#include 
int main() {
    int x;
    x = 2, 3;
    std::cout << x << \"\\n\";
    r         


        

Answer 1

This statement:

  x = 2,3;

is composed by two expressions:

> x = 2
> 3

Since operator precedence, = has more precedence than comma ,, so x = 2 is evaluated and after 3. Then x will be equal to 2.

---

In the return instead:

int f(){ return 2,3; }

The language syntax is :

return 

Note return is not part of expression.

So in that case the two expression will be evaluated will be:

> 2
> 3

But only the second (3) will be returned.