How this c++ code work

First of all merry xmas guys....
i have this c++ code but i cannot understand why this output is coming plese help......

Code:

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#include<iostream>
using namespace std;


int func(int&x,int y=10)
{
    if(x%y==0)
        return ++x;
    else
        return y--;
}




int main()
{
    int p=20,q=23;
    q=func(p,q);
    cout<<p<<" "<<q<<"\n";        //here the value of q would have become 22 but its still 23 why...
    p=func(q);
        cout<<p<<" "<<q<<"\n";
q=func(p);
    cout<<p<<" "<<q<<"\n";
return 0;


}

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MY OUTPUTS ARE

20 23
10 23
11 11

Code:

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return y--;

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This line is why. Can you figure out why it is? :)

Quote:

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Originally Posted by Ewiv

Code:

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return y--;

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This line is why. Can you figure out why it is? :)

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I was thinking this line is why?

Code:

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int func(int&x,int y=10)

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Edit: But, I think you are correct and its your line posted.
After re-reading the code, I saw the issues you hinted at.

Can't say for sure if the int func line is not intended to be that way, so I chose to ignore it. The return line however is obviously wrong. :)

It looks like a school example. I bet your teacher would be thrilled if you'd ask. (I used to work as a teacher)

This question's answer is as trivial as understanding (?)-- vs --(?). Combined with the fact that it's being passed by value:

Code:

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int y=10

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If it worked as you expected, you would've had:

Code:

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return y-1;

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