Question

用指针和指针运算实现球字符串长度函数strlen。

Answer 1

int strlen(char * str)
{
int length=0;
char * p=str;
while(*p)
{
length++;
p++;
}
return length;
}

调用：

void main()
{
char *pp="hello world";
printf("%d",strlen(pp));
}

Answer 2

int
str_len(char
*p)
{
if(p==NULL)return
0;
int
n=0;
char
*q=p;
while(*q!='\0')
{
n++;
q++;
}
return
n;
}

Answer 3

#include<stdio.h>
int my_strlen(const char *str)
{
const char *p = str;
while (*p!='\0')
{
p++;
}
return p - str;
}
int main()
{
int len = 0;
char arr[10] = "abcdefgh";
len = my_strlen(arr);
printf("%d\n",len);
return 0;
}