char

[mehak]

plz explain the output

#include <stdio.h>
int main(){
int i =300;
char *ptr = (char*)&i;
*++ptr=2;
printf("%d",i);
}

[ajh32]

You initially set 'i' to 300, which in memory is 2c01. You assign the memory address of 'i' to your pointer 'ptr'. Then increment the pointer 'ptr' by 1 and assign 2 to the next memory address. The memory address for 'i' then contains 2c02.

300 is 0x12c
556 is 0x22c

[mehak]

but how does the value of i change?

[ajh32]

The value of i is held at an address in memory, you created a pointer to that same memory address and then changed the contents of that address.