Can anyone explain me the output.
#include<stdio.h>
int main() {
int a[]={10,20,30};
int *p=a;
++*p++;
printf("%d %d %d %d",*p,a[0],a[1],a[2]);
}
output is 20 11 20 30
Postfix incrementation has a higher precedence, so value of second index should have been incremented. Why is the value of first index incremented?
Due to operator precedence,
++*p++ is same as ++(*(p++)).
That is equivalent to:
int* p1 = p++; // p1 points to a[0], p points to a[1]
++(*p1); // Increments a[0]. It is now 11.
That explains the output.
This is because the postfix operator returns the value before the increment. So the pointer is well incremented but the prefix operator still applies to the original pointer value.