Session.08.Introduction to Pointers and References

spatlou

Pointers.

spatlou

mohitvaishnav962

#include<stdio.h>

int main()

{

int *ptr = NULL, x = 3;

//it'll print address = 0

fprintf(stdout, "ptr = %d\n", ptr);

//it'll print ptr = 3

ptr = &x;

fprintf(stdout, "ptr = %d\n", *ptr);

*ptr = 5;

//it'll print ptr = 5

// print x = 5

fprintf(stdout, "ptr = %d\n"

"x = %d\n", *ptr, x);

// *ptr = 3; null pointer assignment error, trying to access the 0th

// location, as 0th location is reserved and is in the

// operating system address space/kernal space

// and user space's program is not allowed to access it,

// its a run time error and a serious one!

return 0;

}

/*

* usage : execute with *ptr = 3 only

* to generate a signal SIGSEGV (segmentation fault).

* Comment the rest, otherwise rest is merely the basic usage of a pointer and the way to bypass this error.

* */