Pls explain how it will work?

Question

int x(int &a,int &b)
{
a=3;
b=4;
return a+b;
};
int main ()
{
int a=2;
int b=7;
int c=x(a,a);
cout<<a<<b<<c;
}

output is coming out to be 478.

Answer 1

you write numbers 4 7 and 8 next to each other without any space, that's why it's 478
function takes references as arguments - to the same variable (in main identified as 'a') you assign values 3 and then 4, only the later is kept. So a is 4 and c is 4+4=8
b is 7 and not changed later

Answer 2

@michal. Thanks ☺
let me tell now what I have understood
correct me if I'm wrong
function x will take the reference of a only.
now when 3 is assigned to a it will also make changes in actual parameter a which will now be holding 3 .
then when 4 is assigned to b , since b also has the reference of a so now , actual parameter a will be holding value 4 so when we return a+b it will return 8 because now basically formal parameters a& b both are holding the value 4.
so values in actual parameters will be a=4,b=7 and c=8
so output will be 478

Answer 3

yes, you are right