#include <cstdlib>
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
class MyString:public string
{
public :
MyString(){}
MyString(const char * ch):string(ch){}
MyString operator+(const MyString & b){
MyString tem;
tem = * this;
tem.operator+=(b);
return tem;
}
MyString operator+(const char * ch){
MyString res;
res = *this + MyString(ch);
return res;
}
string operator()(int start,int len){
return string::substr(start,len);
}
char & operator[](int index){
return string::operator[](index);
}
friend MyString operator+(const char * ch,const MyString & mstr){
MyString res;
res = MyString(ch);
res +=mstr;
return res;
}
};
int main()
{
MyString s1("abcd-"),s2,s3("efgh-"),s4(s1);
MyString SArray[4] = {"big","me","about","take"};
cout << "1. " << s1 << s2 << s3<< s4<< endl;
s4 = s3;
s3 = s1 + s3;
cout << "2. " << s1 << endl;
cout << "3. " << s2 << endl;
cout << "4. " << s3 << endl;
cout << "5. " << s4 << endl;
cout << "6. " << s1[2] << endl;
s2 = s1;
s1 = "ijkl-";
s1[2] = 'A' ;
cout << "7. " << s2 << endl;
cout << "8. " << s1 << endl;
s1 += "mnop";
cout << "9. " << s1 << endl;
s4 = "qrst-" + s2;
cout << "10. " << s4 << endl;
s1 = s2 + s4 + " uvw " + "xyz";
cout << "11. " << s1 << endl;
sort(SArray,SArray+4);
for( int i = 0;i < 4;i ++ )
cout << SArray[i] << endl;
//s1的从下标0开始长度为4的子串
cout << s1(0,4) << endl;
//s1的从下标5开始长度为10的子串
cout << s1(5,10) << endl;
return 0;
}