方法一:
int my_strlen(const char *str)
{
int count = 0;
assert(str != NULL);
while (*str != '\0')
{
count++;
str++;
}
return count;
}
int main()
{
int len = my_strlen("abcdef");//count
printf("len = %d\n", );//6
system("pause");
return 0;
}
方法二:不创建临时变量
int my_strlen(const char* str)
{
assert(str != NULL);
if (*str == '\0')
return 0;
else
return 1 + my_strlen(str + 1);
}
int main()
{
int len = my_strlen("abcdef");
printf("len = %d\n", len);
system("pause");
return 0;
}
方法三:指针相减的方法
int my_strlen(const char* str)
{
const char * start = str;
while (*str != '\0')
{
str++;
}
return str - start;
}
int main()
{
int len = my_strlen("abcdef");
printf("len = %d\n", len);
system("pause");
return 0;
}