C语言局部变量 全局变量 静态局部变量 静态全局变量

建立三个文件，文件名分别为main.c \ head1.c \ head2.c

main.c

#include<stdio.h>#include<stdlib.h>#include<string.h>int A;void show(){volatile static int a ;//静态局部变量(static) 静态局部变量定义时前面加static关键字。a++;f1(a);f2(a);//printf("show: B = %d\n",B);}void main(int *argv, char *args[]){show();show();show();show();int c;static int b = 10;}

head1.c

#include<stdio.h>#include<stdlib.h>#include<string.h>static int B ;int A;void f1(int a){A++,B++;printf("head1.h:f1(%d), A = %d, B = %d\n",a,A,B);}

head2.c

#include<stdio.h>#include<stdlib.h>#include<string.h>static int B;int A;void f2(int a){A += 2, B += 2;printf("head2.h:f2(%d), A = %d, B = %d\n",a,A,B);}

编译与运行结果：

-bash-4.1$ gcc -o a Demo.c head*.c-bash-4.1$ ./ahead1.h:f1(1), A = 1, B = 1head2.h:f2(1), A = 3, B = 2head1.h:f1(2), A = 4, B = 2head2.h:f2(2), A = 6, B = 4head1.h:f1(3), A = 7, B = 3head2.h:f2(3), A = 9, B = 6head1.h:f1(4), A = 10, B = 4head2.h:f2(4), A = 12, B = 8-bash-4.1$