// Scoping.
#include <stdio.h>
void useLocal( void ); // function prototype
void useStaticLocal( void ); // function prototype
void useGlobal( void ); // function prototype
int x = 1; // global variable
// function main begins program execution
int main( void )
{
int x = 5; // local variable to main
printf("local x in outer scope of main is %d\n", x );
{ // start new scope
int x = 7; // local variable to new scope
printf( "local x in inner scope of main is %d\n", x );
} // end new scope
printf( "local x in outer scope of main is %d\n", x );
useLocal(); // useLocal has automatic local x
useStaticLocal(); // useStaticLocal has static local x
useGlobal(); // useGlobal uses global x
useLocal(); // useLocal reinitializes automatic local x
useStaticLocal(); // static local x retains its prior value
useGlobal(); // global x also retains its value
printf( "\nlocal x in main is %d\n", x );
} // end main
// useLocal reinitializes local variable x during each call
void useLocal( void )
{
int x = 25; // initialized each time useLocal is called
printf( "\nlocal x in useLocal is %d after entering useLocal\n", x );
++x;
printf( "local x in useLocal is %d before exiting useLocal\n", x );
} // end function useLocal
// useStaticLocal initializes static local variable x only the first time
// the function is called; value of x is saved between calls to this
// function
void useStaticLocal( void )
{
// initialized once before program startup
static int x = 50;
printf( "\nlocal static x is %d on entering useStaticLocal\n", x );
++x;
printf( "local static x is %d on exiting useStaticLocal\n", x );
} // end function useStaticLocal
// function useGlobal modifies global variable x during each call
void useGlobal( void )
{
printf( "\nglobal x is %d on entering useGlobal\n", x );
x *= 10;
printf( "global x is %d on exiting useGlobal\n", x );
} // end function useGlobal
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