strcpy的四种实现方法

char *strcpy(char *dest, const char * src)

{

        int i;

        char *tdest = dest;

 

        i = 0;

        while ( (dest[i] = src[i]) != 0 ) {

                i++;

        }

 

        return tdest;

}

 

char *strcpy(char *dest, const char *src)

{

        char *tdest = dest;

 

        while ( (*dest = *src) != 0) {

                dest++;

                src++;

        }

 

        return tdest;

}

 

char *strcpy(char *dest, const char *src)

{

        char *tdest = dest;

 

        while ( (*dest++ = *src++) != 0)

                ;

 

        return tdest;

}

 

char *strcpy(char *dest, const char *src)

{

        char *tdest = dest;

 

        while ( *dest++ = *src++ )

                ;

 

        return tdest;

}