【C++】C++标准模板库STL （一） string类的使用详解（3）

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s1("hello world");
  const char* str1 = s1.c_str();
  cout << str1 << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s1("hello world");
  /*const char* str1 = s1.c_str();
  cout << str1 << endl;*/
  char ch = 'a';
  char* str1 = &ch;
  s1.copy(str1, 3, 2); // 注意此函数不会拷贝完后追加字符串，打印字符串时要小心越界。
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  //buffer (3)  
  string s1("hello world");
  const char* str = "world";
  int index = s1.find(str, 0, 3);
  cout << index << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  //c-string (2)  
  string s1("hello world");
  const char* str = "world";
  int index = s1.rfind(str);
  cout << index << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s1("hello world");
  int index = s1.find_first_of("wor");
  cout << index << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s1("hello world");
  string s2 = s1.substr(2, 3);
  cout << s2 << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  //string (1)  
  string s1("hello world");
  string s2("iello");
  cout << s1.compare(s2) << endl;
  return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s1;
  //这里我们输入"hello world!"
  getline(cin, s1);
  cout << s1 << endl;
  return 0;
}