c - Different programs, same variables, same address in memory -

i have 2 c codes. test.c

#include <stdlib.h>  int main () {     int a;     = 5;     return a; } 

test2.c is

#include <stdlib.h>  int main () {     int a;     = 6;     return a; } 

when run them , check address in memory of "a"s gdb same address. why so?

breakpoint 1, main () @ test.c:7 7 return a; (gdb) print &a $1 = (int *) 0x7fffffffe1cc

breakpoint 1, main () @ test2.c:7 7 return a; (gdb) print &a $1 = (int *) 0x7fffffffe1cc

the address of "a" on stack frame program. virtual address, independent of in physical memory program loaded. therefore, not surprising if both (almost identical) programs used same address.