Thread: global scope and pointers

Is that your entire code?

I ask, because what you gave us should have set off a cascade of compiler errors about missing entry points, mismatched braces and other things...

Originally Posted by grytskiv

my code:

Code:

#include <stdio.h>

int *pPointer;

void
my_function()
{
 int nNumber;
 nNumber = 25;
 pPointer = &nNumber;
}

int main()
{
 my_function();
 printf("Value of *pPointer: %d\n", *pPointer);
}

terminal:

Code:

grytskiv@ZXDSL831II:~/scope$ gcc -ansi function.c -o function && ./function
Value of *pPointer: 25
grytskiv@ZXDSL831II:~/scope$

I recive value of "nNumber" variable. But "nNumber" is must deleted after complete execution function "my_function".

Why I recive value of removed variable?
May be this variable deleted but pice memory don't nulled, and this pice can modification other proccess or thread?

That's more like it...

You are getting the value of nNumber simply because it hasn't been overwritten yet, and that could happen at any instant. It's called "undefined behavior" and it is to be avoided at all costs.

C does not error trap these things... so you have to.