C library functions achieve strcat

char* strcat(char* dest,const char* src)
{
	char* ret;

	ret = dest;  //保存目的字符串首地址以便返回
	while (*dest++);
	dest--;
	while (*dest++ = *src++);

	return ret;
}


int main()
{
	char dest[100] = "hello";
	char src[] = "world";

	strcat(dest, src);
	cout << dest << endl;

	system("pause");
	return 0;
}