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const字符串

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看代码应该比较明白，记录一下，防止忘记。也欢迎各位随时指正。

一段简单的C语言程序，关于const、字符串。

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

static void pp(void)
{
    char str1[] = "abc"; 
    char str2[] = "abc"; 
    const char str3[] = "abc"; 
    const char str4[] = "abc"; 
    const char *str5 = "abc"; 
    const char *str6 = "abc"; 
    char *str7 = "abc"; 
    char *str8 = "abc";

    printf("%d\n",str1 == str2);//0
    printf("%d\n",str3 == str4);//0
    printf("%d\n",str5 == str6);//1
    printf("%d\n",str7 == str8);//1

    printf("%d\n",str6 == str7);//1
}

int getNum()
{
    return 100;
}

int main()
{
    int n = 90;
    const int MaxNum1 = getNum();  //运行时初始化
    const int MaxNum2 = n;  //运行时初始化
    const int MaxNum3 = 80;  //编译时初始化
    printf("%d, %d, %d\n", MaxNum1, MaxNum2, MaxNum3);

    const char *str1 = "cbiancheng";
    char *str2;
    printf("str1:%s\n",str1);

    str2=malloc(8);
    if(str2!=NULL)
    {
        *str2='b';
        printf("str2:%s\n",str2);
    }

    //char *str3 = (char *)str1;
    //*str3='c';//这里会有错误

    pp();

    return 0;
}

运行结果

str1,str2,str3,str4是数组变量，它们有各自的内存空间；而str5,str6,str7,str8是指针，它们指向相同的常量区域。