C++에서 string 의 용법 과 예 를 자세히 설명 합 니 다.

string s;//    string   
string ss[10];//    string     

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 string s;//     ，      
 string s1("ssss");//s1    “ssss”   
 string s2(s1);//s2 s1   
 string s3=s2;//s3 s2   
 string s4(10,'c');// s4   
 string s5="hiya";//     
 string s6=string(10,'c');//     ，           ，   s6
 //string s(cp,n)
 char cs[]="12345";
 string s7(cs,3);//     cs  3    s  
 //string s(s2,pos2)
 string s8="asac";
 string s9(s8,2);// s2          ，    s2 size
 //string s(s2,pos2,len2)
 string s10="qweqweqweq";
 string s11(s10,3,4);//s4 s3   3  4      ，  s3.size     
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 string s="abcdefg";
 //s.substr(pos1,n)        pos1   n       
 string s2=s.substr(1,5);//bcdef
 //s.substr(pos)//    pos     
 string s3=s.substr(4);//efg
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 string str="to be question";
 string str2="the ";
 string str3="or not to be";
 string::iterator it;
 //s.insert(pos,str)// s pos    str
 str.insert(6,str2);     // to be the question
 //s.insert(pos,str,a,n) s pos    str     a    n   
 str.insert(6,str3,3,4);    // to be not the question
 //s.insert(pos,cstr,n)// pos    cstr          n   
 str.insert(10,"that is cool",8); // to be not that is the question
 //s.insert(pos,cstr) s pos    cstr
 str.insert(10,"to be ");   // to be not to be that is the question
 //s.insert(pos,n,ch) s.pos      n ch
 str.insert(15,1,':');    // to be not to be: that is the question
 //s.insert(s.it,ch) s it            ch，            
 it = str.insert(str.begin()+5,','); // to be, not to be: that is the question
 //s.insert(s.it,n,ch)// s it          n ch
 str.insert (str.end(),3,'.');  // to be, not to be: that is the question...
 //s.insert(it,str.ita,str.itb) it           [ita,itb)    
 str.insert (it+2,str3.begin(),str3.begin()+3); // to be, or not to be: that is the question...
 return 0;
}

#include <iostream>
#include <string>
int main ()
{
 std::string str ("This is an example sentence.");
 std::cout << str << '
';
       // "This is an example sentence."
 str.erase (10,8);  //   ^^^^^^^^
 //                  8   
 std::cout << str << '
';
       // "This is an sentence."
 str.erase (str.begin()+9);//   ^
 //          
 std::cout << str << '
';
       // "This is a sentence."
       //  ^^^^^
 str.erase (str.begin()+5, str.end()-9);
 //          
 std::cout << str << '
';
       // "This sentence."
 return 0;
}

#include <iostream>
#include <string>
int main ()
{
 std::string str;
 std::string str2="Writing ";
 std::string str3="print 10 and then 5 more";
 //      str2    
 str.append(str2);      // "Writing "
 //    str3 6      3    
 str.append(str3,6,3);     // "10 "
 //         5   
 str.append("dots are cool",5);   // "dots "
 //    
 str.append("here: ");     // "here: "
 //  10 '.'
 str.append(10u,'.');     // ".........."
 //  str3         
 str.append(str3.begin()+8,str3.end()); // " and then 5 more"
 //        ，     5 'A'，        65   asc   65
 str.append<int>(5,65);    // "....."
 //                
 str+="lalala";
 std::cout << str << '
';
 return 0;
}

#include <iostream>
#include <string>
int main ()
{
 std::string base="this is a test string.";
 std::string str2="n example";
 std::string str3="sample phrase";
 std::string str4="useful.";
 // replace signatures used in the same order as described above:
 // Using positions:     0123456789*123456789*12345
 std::string str=base;   // "this is a test string."
 // 9        4    str2  
 str.replace(9,5,str2);   // "this is an example string." (1)
 // 19         5    str  7        5     
 str.replace(19,6,str3,7,6);  // "this is an example phrase." (2)
 // 8        9           
 str.replace(8,10,"just a");  // "this is just a phrase."  (3)
 // 8        5           7     
 str.replace(8,6,"a shorty",7); // "this is a short phrase." (4)
 // 22     0    3     
 str.replace(22,1,3,'!');  // "this is a short phrase!!!" (5)
 //        
 // Using iterators:            0123456789*123456789*
 str.replace(str.begin(),str.end()-3,str3);     // "sample phrase!!!"  (1)
 str.replace(str.begin(),str.begin()+6,"replace");    // "replace phrase!!!"  (3)
 str.replace(str.begin()+8,str.begin()+14,"is coolness",7); // "replace is cool!!!" (4)
 str.replace(str.begin()+12,str.end()-4,4,'o');    // "replace is cooool!!!" (5)
 str.replace(str.begin()+11,str.end(),str4.begin(),str4.end());// "replace is useful." (6)
 std::cout << str << '
'; 
 return 0;
}

#include <iostream>
#include <string>
int main ()
{
 std::string str;
 std::string base="The quick brown fox jumps over a lazy dog.";
 // used in the same order as described above:
 //   base   str
 str.assign(base);
 std::cout << str << '
';
 // base 10        8     str
 str.assign(base,10,9);
 std::cout << str << '
';   // "brown fox"
 //     0 6      str
 str.assign("pangrams are cool",7);
 std::cout << str << '
';   // "pangram"
 //        
 str.assign("c-string");
 std::cout << str << '
';   // "c-string"
 // str  10 '*'  
 str.assign(10,'*');
 std::cout << str << '
';   // "**********"
 //   10 '-'
 str.assign<int>(10,0x2D);
 std::cout << str << '
';   // "----------"
 //  base         
 str.assign(base.begin()+16,base.end()-12);
 std::cout << str << '
';   // "fox jumps over"
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 std::string str ("There are two needles in this haystack with needles.");
 std::string str2 ("needle");
 // different member versions of find in the same order as above:
 // str          needle，          ，      
 std::size_t found = str.find(str2);
 if (found!=std::string::npos)
 std::cout << "first 'needle' found at: " << found << '
';
 // str  ，  found+1              6   
 found=str.find("needles are small",found+1,6);
 if (found!=std::string::npos)
 std::cout << "second 'needle' found at: " << found << '
';
 // str           
 found=str.find("haystack");
 if (found!=std::string::npos)
 std::cout << "'haystack' also found at: " << found << '
';
 //      
 found=str.find('.');
 if (found!=std::string::npos)
 std::cout << "Period found at: " << found << '
';
 //    ， str2           
 // let's replace the first needle:
 str.replace(str.find(str2),str2.length(),"preposition");
 std::cout << str << '
';
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 std::string str ("The sixth sick sheik's sixth sheep's sick.");
 std::string key ("sixth");//     ^
 //rfind              
 std::size_t found = str.rfind(key);
 if (found!=std::string::npos)
 {
  cout<<found<<endl;//  23
  str.replace (found,key.length(),"seventh");//   sixth   seventh
 }
 std::cout << str << '
';
 return 0;
}

find_first_of(args)   args               
find_last_of(args)          
find_fist_not_of(args)        args    
find_last_not_of         args      
#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 std::string str1 ("Please, replace the vowels in this sentence by asterisks.");
 std::size_t found1 = str1.find_first_of("aeiou");
 //         *  
 while (found1!=std::string::npos)
 {
  str1[found1]='*';
  found1=str1.find_first_of("aeiou",found1+1);
 }
 std::cout << str1 << '
';
 // str2                    
 std::string str2 ("look for non-alphabetic characters...");
 std::size_t found2 = str2.find_first_not_of("abcdefghijklmnopqrstuvwxyz ");
 if (found2!=std::string::npos)
 {
  std::cout << "The first non-alphabetic character is " << str2[found2];
  std::cout << " at position " << found2 << '
';
 }
 return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 string s1="123",s2="123";
 cout<<s1.compare(s2)<<endl;//0
 s1="123",s2="1234";
 cout<<s1.compare(s2)<<endl;//-1
 s1="1234",s2="123";
 cout<<s1.compare(s2)<<endl;//1
 std::string str1 ("green apple");
 std::string str2 ("red apple");
 if (str1.compare(str2) != 0)
 std::cout << str1 << " is not " << str2 << '
';
 //str1  6        4        
 if (str1.compare(6,5,"apple") == 0)
 std::cout << "still, " << str1 << " is an apple
";
 if (str2.compare(str2.size()-5,5,"apple") == 0)
 std::cout << "and " << str2 << " is also an apple
";
 //str1  6        4    str2  4        4     
 if (str1.compare(6,5,str2,4,5) == 0)
 std::cout << "therefore, both are apples
";
 return 0;
}

//  ，     MinGw    ！    c++11     ，    to_string！
#include <bits/stdc++.h>
using namespace std;
int main()
{
 ios::sync_with_stdio(false);
 string s1;
 s1=to_string(100);
 cout<<s1<<endl;
 int a=stoi(s1,0,10)+1;
 cout<<a<<endl;
 return 0;
}