第17章 string基本字符序列容器

/*

  第17章 string基本字符序列容器
   17.1 string技术原理
   17.2 string应用基础
   17.3 本章小结

*/



//  第17章 string基本字符序列容器
//   17.1 string技术原理 --------------------------------------------------------------------------------------

//   17.2 string应用基础 --------------------------------------------------------------------------------------


//259
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  string s1;
  s1.push_back(‘a‘);
  s1.push_back(‘b‘);
  s1.push_back(‘c‘);
  cout << "打印s1: " << s1 << endl;
  //
  char *cArray = "efgh";
  string s2(cArray);
  cout << "打印s2: " << s2 << endl;
  //字符串的"+"操作
  cout << "打印s1+s2: " << s1 + s2 << endl;
  //字符串s1后添加字符串s2
  cout << "append后,打印s1: " << s1.append(s2) << endl;
  //在s1的第2个字符位置前插入字符‘8‘
  string::iterator i;
  i = s1.begin();
  i++;
  s1.insert(i, ‘8‘);
  cout << "insert后,打印s1: " << s1 << endl;
  //字符串的"+="操作
  s1 += s2;
  cout << "s1+=s2后,打印s1: " << s1 << endl;
  return 0;
}


//260 遍历字符
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  char *cArray = "hello, world!";
  string s(cArray);
  //数组方式
  for(unsigned int j = 0; j < s.size(); j++)
    cout << "第" << j << "个字符: " << s[j] << endl;
  //迭代器方式
  string::reverse_iterator ri, rend;
  rend = s.rend();
  cout << "反向打印字符" << endl;
  for(ri = s.rbegin(); ri != rend; ri++)
    cout <<  *ri << ‘ ‘;
  cout << endl;
  return 0;
}


//261 erase
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  char *cArray = "a12345678b";
  string s(cArray);
  s.erase(s.begin());
  cout << s << endl; //打印出12345678b
  //
  s.erase(s.begin() + 3, s.end() - 2);
  cout << s << endl; //打印出1238b
  //
  s.erase(0, 2);
  cout << s << endl; //打印38b
  //
  s.clear();
  return 0;
}


//262 replace
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  char *cArray1 = "hello,boy!";
  string s(cArray1);
  //
  s.replace(6, 3, "gril"); //boy替换为girl
  cout << s << endl; //打印hello gril!
  //
  s.replace(10, 1, 1, ‘.‘); //将"hello gril!"的‘!‘替换为‘.‘
  cout << s << endl; //打印hello gril.
  //
  s.replace(s.begin(), s.begin() + 5, "good morning");
  cout << s << endl; //打印good morning girl.
  return 0;
}



//263, find
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  //0123456789012345678901234
  string s("dog bird chicken bird cat");
  //字符串查找
  cout << s.find("bird") << endl; //打印4
  cout << (int)s.find("pig") << endl; //打印-1
  //字符查找
  cout << s.find(‘i‘, 7) << endl; //打印11
  //从字符串的末尾开始查找字符串
  cout << s.rfind("bird") << endl; //打印17
  //从字符串的末尾开始查找字符
  cout << s.rfind(‘i‘) << endl; //打印18
  //查找第1个属于某子串的字符
  cout << s.find_first_of("13r98") << endl; //找到字符r,打印6
  //查找第1个不属于某字符串的字符
  cout << s.find_first_not_of("dog bird 2006") << endl; //找到字符c,打印9
  //查找最后一个属于某子串的字符
  cout << s.find_last_of("13r98") << endl; //字符r,打印19
  //查找最后一个不属于某字符串的字符
  cout << s.find_last_not_of("tea") << endl; //字符c,打印22
  return 0;
}


//263-264, compare
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  string s1("abcdef");
  string s2("abc");
  cout << s1.compare("abcdef") << endl; //相等,打印0
  cout << s1.compare(s2) << endl; //s1 > s2,打印1
  cout << s1.compare("abyz") << endl; //s1 < "abyz",打印-1
  //
  cout << s1.compare(0, 3, s2) << endl; //s1的前3个字符==s2,打印0
  return 0;
}


//264
#include <string>
#include <iostream>
int main(void)
{
  using namespace std;
  string s;
  cout << s.empty() << endl; //空字符串,返回1
  s += "1234567";
  cout << s.empty() << endl; //不为空,返回0
  cout << s.size() << endl; //7个字符,返回7
  cout << s.length() << endl; //返回7
  //
  const char *cArray = s.c_str();
  cout << cArray[2] << endl; //返回字符3
  return 0;
}



//   17.3 本章小结 --------------------------------------------------------------------------------------