int a = 0; //全局初始化区
char *p1; //全局未初始化区
main()
{
int b; //栈
char s[] = "abc "; //栈
char *p2; //栈
char *p3 = "123456 "; //123456在常量区,p3在栈上
static int c =0; //全局(静态)初始化区
p1 = (char *)malloc(10);
p2 = (char *)malloc(20);//分配得来得和字节的区域就在堆区
strcpy(p1, "123456 "); //123456放在常量区,编译器可能会将它与p3所指向的"123456 "优化成一个地方
}