string

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 int main()
 5 {
 6     string s1="value";;
 7     string s2(s1);
 8     string s3=s1;
 9     string s4("value");
10     string s5(10,‘n‘);  //初始化10个n的字符串
11     cout<<s1<<endl;
12     cout<<s2<<endl;
13     cout<<s3<<endl;
14     cout<<s4<<endl;
15     cout<<s5<<endl;
16 
17 }

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 int main()
 5 {
 6     string s1;
 7     string s2;
 8     getline(cin,s1);//从cin中读取一行赋值给s1
 9     cin>>s2;//从cin流中读取一个字符串赋值给s2 
10     cout<<s1.empty()<<endl;//空串返回1 
11     cout<<s2.size()<<endl;//字符串大小 
12        cout<<s2[0]<<endl;//返回第一个引用 
13        cout<<s1+s2<<endl;//s1和s2连接 
14        cout<<(s1==s2)<<endl;//判断是s1和s2是否相等 
15     cout<<(s1!=s2)<<endl;
16 }

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 int main()
 5 {
 6     string s1;
 7     cin>>s1;//从cin流中读取一个字符串赋值给s2 
 8     cout<<s1; 
 9 
10 }