#include <iostream>
#include <string>
using namespace std;
typedef string String;

int main() {
  // 默认构造函数，没有参数
  string s1;
  // 赋值运算
  s1 = "hello";
  cout << s1 << endl;

  // 拷贝构造函数，等价于 string s2 = "hello";
  string s2("hello");
  cout << s2 << endl;

  // 拷贝构造函数
  String s3("world!");
  cout << s3 << endl;

  // args: (C string, number of chars)
  string s4("this is a C string", 10); // output is "this is a "
  cout << "s4 is " << s4 << endl;

  // args: （C++ string, start position, number of characters)
  string s5(s4, 3, 3);
  cout << "s5 is " << s5 << endl;

  // args: (number of characters, char)
  string s6(6, '#');
  cout << "s6 is " << s6 << endl;

  // args: (start, end)
  string s7(s4.begin(), s4.end()-3);
  cout << "s7 is " << s7 << endl;

  string s8 = s7 + s6;
  cout << "s8 is " << s8 << endl;

  for(int i=0; i!=s8.size(); i++) {
    cout << i << " " << s8[i] << " ";
  }
  cout << endl;

  // 常量迭代器const_iterator；变量迭代器 iterator
  string::const_iterator ii;
  int i = 0;
  for(ii=s8.begin(); ii!=s8.end(); ii++) {
    cout << i++ << " " << *ii << endl;
  }

  return 0;
}