变量在内存中的区域

变量在内存中的区域

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int i1 = 10; 
int i2 = 20; 
int i3;     
const int i4 = 40;

void fn(int i5) 
{
    int i6 = 60;
    static int i7 = 70;
    const int i8 = 80; 
    int* p1 = (int*)malloc(sizeof(int));
    int* p2 = (int*)malloc(sizeof(int));
    char* str = "good";  //等号两端是不同的数据类型，右端自动转型成char*，而"good"这个char数组仍然没有名字。
    //str="abcd";
    //strcpy(str,"12345");
    //str = (char*)malloc(sizeof(char)*10);
    //strcpy(str,"12345");
    //char* pt = str;
    //free(pt);
    //pt = NULL;
    //str = "hello,world";
//    printf("str=%s\n",str);

    char strs[] = "good"; //等号两端是相同的数据类型，右值成为左值
    //strs = "hjkl";
    //strcpy(strs,"hjkl");
    //printf("strs=%s\n",strs);

    //............
printf("--------BSS（未初始化的或为0的）区-----------\n");
printf("&i3 = %p\n", &i3); 
printf("---------只读区------------\n");
printf("&i4 = %p\n", &i4);
printf("str = %p\n", str);
printf("---------全局变量区------------\n");
printf("&i7 = %p\n", &i7);
printf("&i1 = %p\n", &i1); 
printf("&i2 = %p\n", &i2); 
printf("---------堆区-----------\n");
printf("&(* p1) = %p\n", p1);
printf("&(* p2) = %p\n", p2);
printf("---------栈区------------\n");
printf("&str = %p\n", &str);//str指向该常量地址
printf("strs = %p\n", strs);//str在栈上申请空间，将常量内容复制进来，所以是局部变量
printf("&i8 = %p\n", &i8);
printf("&i5 = %p\n", &i5);
}

int main(void)
{
    int i0=10;
    printf("------代码区的符号或数据--------\n");
printf("&main = %p\n", main); 
    printf("------栈区的符号或数据--------\n");
    printf("&i0 = %p\n",&i0);

    fn(i0);
    return 0;
}

char str[ ]和char str = （char） malloc（n*）
链接：http://blog.youkuaiyun.com/yahohi/article/details/7427724

char * strcpy(char * strDest,const char * strSrc)

{

char * strDestCopy=strDest; //

if ((strDest==NULL)||(strSrc==NULL)) //[1]

throw "Invalid argument(s)"; //[2]

while ((*strDest++=*strSrc++)!='\0'); //

return strDestCopy;

}