[学习笔记][C++Primer Plus]String类的使用

1.构造字符串

//1. string(const char * s) string one("This is a string"); cout << one << endl;   //2. string(size_type n, char c) string two(20,'$'); cout << two << endl;   //3.string(const string &str, string size_type pos=0, size_type n = npos) string three(one); cout << three << endl;   one += ". hello world"; cout << one << endl;   two = "Change two"; cout << two << endl;   three[0] = 'P'; cout << three << endl;   //4. string() string four; four = two + three; cout << four << endl;   //5. string(const char *s, size_type n) char alls[] = "abcdefghijklmnopqrstuvwxyz"; string five(alls,20); cout << five << endl;   //6. template<class Iter) //7. string(Iter begin, Iter end) string six(alls+6,alls+10); cout << six << endl;   string seven(&five[6], &five[10]); cout << seven << endl;

输出结果如下： This is a string $$$$$$$$$$$$$$$$$$$$ This is a string This is a string. hello world Change two Phis is a string Change twoPhis is a string abcdefghijklmnopqrst ghij ghij Press any key to continue

2.输入字符串

// C风格的字符串，如果长度大于10会怎么样？     /*     char info[10];     cin >> info;     cin.getline(info,10);     cin.get(info, 10);     */       string word;     cout << "Enter a line: ";     cin >> word;     while(cin.get()!='\n')     {         continue;     }     cout << word << " is all I wanted." << endl;       string line;     cout << "Enter a line (really!): ";     getline(cin, line); // 使用getline(istream &, string &)     cout << "Line: " << line << endl;

输出结果： Enter a line: aaaaa bbbbb ccccc ddddddd aaaaa is all I wanted. Enter a line (really!): aaaaa bbbbb ccccc ddddddd Line: aaaaa bbbbb ccccc ddddddd