字符串与常规char数组的区别

wmsok

C++ Primer Plus第6版中文版 程序清单7.9 strgfun.cpp

  ----书上有这么一段话：“ 但字符串与常规char数组只是数组之间的一个重要区别是，字符串有内置的结束字符，而char数组只是数组不是字符串。这意味着不用将字符串的长度作为参数传递给函数，而函数可以使用循环依次检查字符串中的每个字符，直到遇到结尾的空值字符为止。”
然后附了下面这段例子，但我没的看出有什么区别，求教！！

1. 
   
2. 
   
3. #include "stdafx.h"
   
4. #include <iostream>
   
5. using namespace std;
   
6. 
   
7. unsigned int c_in_str(const char * str, char ch);
   
8. 
   
9. int _tmain(int argc, _TCHAR* argv[])
   
10. {
    
11. 
    
12.     char mmm[15] = "minimum";    // string in an array
    
13. // some systems require preceding char with static to
    
14. // enable array initialization
    
15. 
    
16.     char *wail = "ululate";    // wail points to string
    
17. 
    
18.     unsigned int ms = c_in_str(mmm, 'm');
    
19.     unsigned int us = c_in_str(wail, 'u');
    
20.     cout << ms << " m characters in " << mmm << endl;
    
21.     cout << us << " u characters in " << wail << endl;
    
22.     cin.get();
    
23.     return 0;
    
24. }
    
25. 
    
26. // this function counts the number of ch characters
    
27. // in the string str
    
28. unsigned int c_in_str(const char * str, char ch)
    
29. {
    
30.     unsigned int count = 0;
    
31. 
    
32.     while (*str)        // quit when *str is '\0'
    
33.     {
    
34.         if (*str == ch)
    
35.             count++;
    
36.         str++;        // move pointer to next char
    
37.                 cout <<*str<<endl;
    
38.     }
    
39.        
    
40.     return count;
    
41. }
    

复制代码

wkj611

#include<stdio.h>
int main(int argc,char *argv[])
{
        char *a = "wkj";
        char b[3] = "wkj";
        xunhuan(a);
        xunhuan(b);
        return 0；

}
int xunhuan(char *a)
{
        int count = 0;
        while(*a)
        {count++;a++;}
        printf("%d\n",count);

}

输出:
3
11

bjutslg

你把数组这样赋值就能看出区别了

1. char mmm[15];
   
2. mmm[0]='m';
   
3. mmm[1]='i';
   
4. mmm[2]='n';
   
5. mmm[3]='i';
   
6. mmm[4]='m';
   
7. mmm[5]='u';
   
8. mmm[6]='m';

复制代码

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