An example of C-language local variables and global variables

#include <stdio.h>

int x = 77; /* global variable x*/

void Fn1 ()

{

extern int y; /* Use external global variable y, if no extern compilation does not pass */

printf ("Fn1 (): x=%d,y=%d\n", x, y); x=77,y=88;

}

void Fn2 ()

{

extern int y; /* Use external global variable y, if no extern compilation does not pass */

y=888; /* Modify the external global variable Y to 888*/

printf ("Fn2 (): x=%d,y=%d\n", x, y); x=77,y=888;

}

int y = 88; /* global variable y*/

void Fn3 ()

{

printf ("Fn3 (): x=%d,y=%d\n", x, y); X=77,y=888,y does not need to use extern because Y is defined in front of FN3 ().

}

int main ()

{

int x = 10; Local variables within the/*main method x*/

if (x>0)

{

int x = 100; /*if local variables within a statement x*/

x/=2;

printf ("If statement inside, x=%d\n", X); x=50;

}

printf ("Main method inside, x=%d\n", x);//x=10;

FN1 ();

FN2 ();

Fn3 ();

Getch ();

return 0;

}

Operation Result:

------------------------------------------

Within the IF statement, x=50

Within the main method, x=10

FN1 (): x=77,y=88

FN2 (): x=77,y=888

Fn3 (): x=77,y=888

This article is from the Java Technology Alliance blog, so be sure to keep this source http://simoniu.blog.51cto.com/2566344/1591746

An example of C-language local variables and global variables