Question

c语言编程函数

编写一个strlen函数，它能对一个字符串测出其长度，函数返回值就是字符串的长度。（说明：字符串的长度不包括空操作终止符“\0”

Answer 1

/*function: 测量字符串长度
*in: 需要测长度的字符串
*out: 字符串长度
*/
int strlen(string str)
{
assert( str != NULL ); // #include <assert.h>
char *ch = NULL;
int iLength = 0;
ch = str;
while ( *ch != '\0')
{
ch = ch + 1;
iLength = iLength + 1;
}
return iLength;
}

Answer 2

#include <stdio.h>

int Strlen(char *str);

int main(int argc, char *argv[])
{
char *tmp = "faadfj";
printf("strlen = %d\n", Strlen(tmp));

return 0;
}

int Strlen(char *str)
{
if( !str )
return 0;

int len = 0;
char *tmp = str;
while ( *tmp!='\0')
{
tmp++;
len++;
}

return len;
}

Answer 3

int mystrlen(char *str)
{
char *tmp=str;
while(*str++);
return str-tmp-1;
}

Answer 4

int strlen(char* str)
{
register int a = 0;
while(*str++)a++;
return a;
}

Answer 5

int
slen(s)
char *s;
{
register char *p = s;

while(*p)
p++;
return(p - s);
}