temp.txt

重载＋＝为字符串的连接

//以对String对象的引用额形式返回
//返回以index开始长度为subLength的子串
String &String:: operator() (int pos, int subLength)
{
	String *subPtr;

	if(length==0||pos+subLength>=length)
		length=length-pos+1;
	else
		length=subLength;

	subPtr=new char[length+1];
	strcpy(subPtr, sPtr[pos]);
	delete []sPtr;	// 释放内存
	
	return *tempPtr;	//返回对子串的引用
}