split_string

vector<string> split(const string &s, const string &seperator){
  vector<string> result;
  typedef string::size_type string_size;
  string_size i = 0;
  
  while(i != s.size()){
    //找到字符串中首個(gè)不等于分隔符的字母；
    int flag = 0;
    while(i != s.size() && flag == 0){
      flag = 1;
      for(string_size x = 0; x < seperator.size(); ++x)
      if(s[i] == seperator[x]){
          ++i;
          flag = 0;
      break;
    }
    }
    
    //找到又一個(gè)分隔符，將兩個(gè)分隔符之間的字符串取出；
    flag = 0;
    string_size j = i;
    while(j != s.size() && flag == 0){
      for(string_size x = 0; x < seperator.size(); ++x)
    if(s[j] == seperator[x]){
      flag = 1;
    break;
}
      if(flag == 0) 
++j;
    }
    if(i != j){
      result.push_back(s.substr(i, j-i));
      i = j;
    }
  }
  return result;
}

void split_string(const std::string& s, std::vector<std::string>& v, const std::string& c)
{
    std::string::size_type pos1, pos2;
    pos2 = s.find(c);
    pos1 = 0;
    while (std::string::npos != pos2)
    {
        v.push_back(s.substr(pos1, pos2 - pos1));
        pos1 = pos2 + c.size();
        pos2 = s.find(c, pos1);
    }
    if (pos1 != s.length())
        v.push_back(s.substr(pos1));
}

C++string函數(shù)

賦值assign()

將字符串2賦值給字符串1：

1. 字符串1 = 字符串2;
2. 字符串1.assign(字符串2);

string s1="I'm";
string s2;
s2="1234";
s1.assign(s2);
cout<<s1;
//輸出結(jié)果：1234

將字符串2從第m個(gè)字符開始的n個(gè)字符賦值給字符串1：
字符串1.assign(字符串2, m, n);

string s1="I'm";
string s2="12345678";
s1.assign(s2,4,3);
cout<<s1;
//輸出結(jié)果：567

長度length()、size()

返回字符串長度： 1. 字符串1.length(); 2. 字符串1.size();

string s1 = "1234Juruo1234";
cout << s1.length() << endl;
cout << s1.size() <<endl;
//輸出結(jié)果：13

比較

">", "<", "==", ">=", "<="均可以用于字符串比較。

string PPAP[] = {"I", "have", "a", "pen", "an", "apple", "um", "apple-pen"};
sort(PPAP, PPAP + 8);
for(int i = 0; i < 8; i++){
    cout << PPAP[i] << endl;
}
/*
輸出結(jié)果：
I
a
an
apple
apple-pen
have
pen
um
*/

查找

在字符串1中從第m個(gè)字符開始查找字符串2，返回第一次出現(xiàn)的首字母位置，失敗時(shí)返回-1：
字符串1.find(字符串2, m);

string s1 = "ggabcdabcgggabcdefg";
string s2 = "gg";
int pos = -1;
while(1){
    pos = s1.find(s2, pos+1);
    if(pos == -1) break;
    cout << pos << ' ';
}
//輸出結(jié)果：0 9 10 

在字符串1中從第m個(gè)字符開始從后向前查找字符串2，返回第一次出現(xiàn)的首字母位置，失敗時(shí)返回-1：
字符串1.rfind(字符串2, m);

string s1 = "ggabcdabcgggabcdefg";
string s2 = "gg";
int pos = s1.length();
while(pos > 0){
    pos = s1.rfind(s2, pos-1);
    if(pos < 0) break;
    cout << pos << ' ';
}
//輸出結(jié)果：10 9 0;

連接

將字符串2接到字符串1尾部：

1. 字符串1.append(字符串2); //字符不可
2. 字符串1 += 字符串2; //字符亦可

string s1 = "I'm ";
string s2 = "Juruo";
s1.append(s2);// 或 s1 += s2;
cout << s1;//輸出結(jié)果：I'm Juruo

將字符串2從第m個(gè)字符開始的n個(gè)字符接到字符串1尾部：
字符串1.append(字符串2, m, n);

string s1 = "I'm ";
string s2 = "1234Juruo1234";
s1.append(s2, 4, 5);
cout << s1;//輸出結(jié)果：I'm Juruo

交換

字符串1.swap(字符串2);

string s1 = "I'm ";
string s2 = "Juruo";
s1.swap(s2);
cout << s1 << endl;//輸出結(jié)果：Juruo

子串

返回字符串1從第m個(gè)字符開始的n個(gè)字符所組成的子串：
字符串1.substr(m, n);

string s1 = "I'm ";
string s2 = "1234Juruo1234";
s1 = s2.substr(4, 5);
cout << s1 << endl;//輸出結(jié)果：Juruo

替換

在字符串1中刪除從m開始的n個(gè)字符，然后在m處插入串s2
字符串1.replace(m, n, s2);

string s1 = "I'm Juruo";
string s2 = "Juruo";
string s3 = "Dalao";
int pos = s1.find(s2);
s1.replace(pos, s2.length(), s3);
cout << s1;//輸出結(jié)果：I'm Dalao

插入

在字符串1的第m個(gè)字符處插入字符串2：
字符串1.insert(m, 字符串2);

string s1 = "I'm Juruo";
string s2 = "not ";
s1.insert(s1.find("Juruo", 0), s2 );
cout << s1 << endl;
//輸出結(jié)果：I'm not Juruo

刪除

從字符串1的第m個(gè)字符開始，刪除n個(gè)字符：
字符串1.erase(m, n);

string s1 = "I'm not Dalao";
s1.erase(s1.find("not"), 4);
cout << s1 << endl;