参数的书写要完整，不要贪图省事只写参数的类型而省略参数名字。
1 #include <iostream> 2 #include <string> 3 4 using namespace std; 5 6 //测试字符串(string)对象 7 /* run this program using the console pauser or add your own getch, system("pause") or input loop */ 8 9 int main(int argc, char** argv) { 10 //创建string对象 11 string s1,s2; 12 13 //string对象的赋值运算 14 s1="One"; 15 s2="Two"; 16 cout<<"s1="<<s1<<endl; 17 cout<<"s2="<<s2<<endl; 18 19 //string对象的连接运算 20 string s3; 21 s3=s1+" and "+s2; 22 cout<<"s3="<<s3<<endl; 23 24 //组合赋值连接运算 25 s3+=" and Three"; 26 cout<<"s3="<<s3<<endl; 27 28 //比较运算及其结果显示 29 for (int i=1;i<=3;i++) { 30 cout<<"---------------------"<<endl; 31 cout<<"s1="; 32 cin>>s1; 33 cout<<"s2="; 34 cin>>s2; 35 if (s1<s2) //小于 36 cout<<s1<<" < "<<s2<<endl; 37 if (s1<=s2) //小于等于 38 cout<<s1<<" <= "<<s2<<endl; 39 if (s1==s2) //等于 40 cout<<s1<<" == "<<s2<<endl; 41 if (s1>s2) //大于 42 cout<<s1<<" > "<<s2<<endl; 43 if (s1>=s2) //大于等于 44 cout<<s1<<" >= "<<s2<<endl; 45 if (s1!=s2) //不等 46 cout<<s1<<" != "<<s2<<endl; 47 } 48 return 0; 49 }