《C++primer》第八章课后习题

练习8.1

istream& abc(istream& is)
{
	string s;
	is >> s;
	cout << s;
	s.clear();
	return is;
}

练习8.2

abc(cin);

练习8.3

答：输入类型与i不符，或者输入结束标识

练习8.4

vector<string> s;
void abc(string s1)
{
	string s2;
	ifstream in(s1);
	while(getline(in, s2))
		s.push_back(s2);
}

练习8.5

vector<string> s;
void abc(string s1)
{
	string s2;
	ifstream in(s1);
	while(in>>s2)
		s.push_back(s2);
}

练习8.6

略

关于书店程序，lz在这里就不写了，想具体了解的同学请看原书。

练习8.9

istringstream& abc(istringstream& is)
{
	string s;
	is >> s;
	cout << s;
	s.clear();
	return is;
}

练习8.10

vector<string> s;
void abc(string s1)
{
	string s2;
	ifstream in(s1);
	while (getline(in, s2))
	{
		s.push_back(s2);
		istringstream is(s2);
		is >> s2;
	}
}

练习8.11

string line,word;
vector<PersonInfo> people;
getline(cin,line);
istringstream record(line);
while(getline(cin,line))
{
	PersonInfo info;
	record>>info.name;//读取名字
	while(record>>word)//读取电话号码
		info.phones.push_back(word);//保持他们
	people.push_back(info);//将此纪录追加到people末尾
}

练习8.12

答：因为希望用默认初始化

练习8.13

string line,word;
vector<PersonInfo> people;
ifstream in("filename");
while(getline(in,line))
{
	PersonInfo info;
	istringstream record(line);
	record>>info.name;
	while(record>>word)
		info.phones.push_back(word);
	people.push_back(info);
}

练习8.14

答：因为不想无意间修改他们的值。