string类型操作

 

/*string的构造函数*//*#include<iostream>using namespace std;#include<string>int main(){string a(4,'c');string b("value");string c(b);cout<<a<<endl;cout<<b<<endl;cout<<c<<endl;//判断字符串是否为空if(!c.empty()){cout<<"c is not empty"<<endl;//string::size_type=c.size();//cout<<string::size_type<<endl;}//按照字符下标输出字符串cout<<c[4]<<endl;//字符串重载+号操作符c+=c;//字符串重载=操作符a=c;if(a==c){cout<<"a is equal to c"<<endl;}cout<<a<<endl;cout<<c<<endl;string d;//输出带空格的字符串的方法getline(cin,d);cout<<d<<endl;//输出带空格后面的字符串的方法string e;while(cin>>e){cout<<e;}return 0;}*//*字符串的赋值*/#include<iostream>using namespace std;#include<string>int main(){string s1="asdf";string s2="sefwe";string s3=s1+s2;string s4="asdfe"+s3;cout<<s4<<endl;cout<<s3<<endl;string::size_type si;for(si=0;si<s4.size();si++)cout<<s4[si]<<endl;if(isalnum(s4[4])){cout<<"yes"<<endl;}if(isdigit(s4[4])){cout<<"is digital"<<endl;}if(isupper(s4[4])){cout<<"is upper alpher"<<endl;}for(si=0;si!=s4.size();si++){s4[si]=toupper(s4[si]);}cout<<s4<<endl;return 0;}