A debate about x++; ⁉️🤔

Hi there, I hope you all are fine
let us talk a little bit about C++ programming language and take a deep dive into assignment operator (=) and post-increment operator (++)

#include <iostream>
using namespace std;
int main()
{
    int x = 5;
    x = x++;
    cout<<x;    // 5
    return 0;
}

The question is why x equals 5?
First of all, let us divide this statement into 3 parts
1) x
2) =
3) x++;
As the assignment operator = assigns the right side to the left side and returns the left side we should start with the right-most part which is x++;

x++ This is a post-increment operator which means it will evaluate the current value (5), and increment the value in memory for the upcoming operations (6).

When you use x++, the value of x is first used in the expression where x++ appears, and then x is incremented by 1.

until now everything is clear?
again
so x++; will do two things,

• it'll give you a temporary value (we can say) which is 5, and,
  change x's real value in memory by 1.

• but, if we say x = 900; we obviously say in this statement:
  change x's real value in memory and assign 900 to it.

If you notice same bold phrase repeated which means the same behavior in 2 different situations normal assignment and post-increment.

so finally the x = part will overwrite (x = 6 in memory) so it will remain 5.
I hope you got it 👍

Comments

[3BiEiD]

You can use pythontutor for more visualization of memory, Actually, it's a very great tool.