C++基础---string类的find/find_first_of/find_first_not_of/rfind/find_last_of/find_last_not_of

1. string类的find/find_first_of/find_first_not_of/rfind/find_last_of/find_last_not_of

1.1 std::string::find

• 原型：size_t find (const string& str, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，查找有目标字符串str(string型字符串)的位置。
• 原型：size_t find (const char* s, size_t pos = 0) const;
• 说明：从源字符串起始位置pos(默认为0)处，查找有目标字符串s(char型字符串)的位置。
• 原型：size_t find (const char* s, size_t pos, size_type n) const;
• 说明：从源字符串起始位置pos处，查找有目标字符串s前n个字符(char型字符串)的位置。
• 原型：size_t find (char c, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，查找有目标字符c的位置。
• 注意：如果找到，则返回首次匹配的开始位置，如果没有找到匹配的内容，则返回string::npos(从字符串的前端开始查找)

• 代码示例：

  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("one two three four one two three four");
  
      cout<<"size_t find (const string& str, size_t pos = npos) const noexcept;"<<endl;
      string str2("one");
      size_t found1 = str1.find(str2);
      if (found1 != string::npos)
      {
          str1.replace(found1, str2.size(), "ONE");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find (const char* s, size_t pos = npos) const;"<<endl;
      size_t found2 = str1.find("two");
      if (found2 != string::npos)
      {
          str1.replace(found2, strlen("two"), "TWO");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find("three", 0, 5);
      if (found3 != string::npos)
      {
          str1.replace(found3, strlen("three"), "THREE");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find (char c, size_t pos = npos) const noexcept;"<<endl;
      size_t found4 = str1.find('f');
      if (found4 != string::npos)
      {
          str1.replace(found4, sizeof('f'), "F");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find (const string& str, size_t pos = npos) const noexcept;
    ONE two three four one two three four
  
    size_t find (const char* s, size_t pos = npos) const;
    ONE TWO three four one two three four
  
    size_t find (const char* s, size_t pos, size_t n) const;
    ONE TWO THREE four one two three four
  
    size_t find (char c, size_t pos = npos) const noexcept;
    ONE TWO THREE Four one two three four

1.2 std::string::find_first_of

• 原型：size_t find_first_of (const string& str, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符在目标字符串str(string型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_first_of (const char* s, size_t pos = 0) const;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符在目标字符串s(char型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_first_of (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos处，依此查找每个字符。如果某字符在目标字符串s前n个字符(char型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_first_of (char c, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符等于目标字符c，则返回首次匹配的该字符的位置。
• 注意：如果没有找到匹配的内容，则返回string::npos(从字符串的前端开始查找)

• 代码示例：

  (1)代码示例一：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz");
  
      cout<<"size_t find_first_of (const string& str, size_t pos = 0) const;"<<endl;
      string str2("aeimqu");
      size_t found1 = str1.find_first_of(str2);
      while (found1 != string::npos)
      {
          str1[found1]='*';
          found1 = str1.find_first_of(str2, found1+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (const char* s, size_t pos = 0) const;"<<endl;
      size_t found2 = str1.find_first_of("dhlptxz");
      while (found2 != string::npos)
      {
          str1[found2]='-';
          found2 = str1.find_first_of("dhlptx", found2+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_first_of("yz", 0, 1);
      while (found3 != string::npos)
      {
          str1[found3]='Y';
          found3 = str1.find_first_of("yz", found3+1, 1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (char c, size_t pos = 0) const;"<<endl;
      size_t found4 = str1.find_first_of('z');
      while (found4 != string::npos)
      {
          str1[found4]='2';
          found4 = str1.find_first_of("z", found4+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_first_of (const string& str, size_t pos = 0) const;
    *bcd *fgh *jkl *nop *rst *vwx yz
  
    size_t find_first_of (const char* s, size_t pos = 0) const;
    *bc- *fg- *jk- *no- *rs- *vw- yz
  
    size_t find_first_of (const char* s, size_t pos, size_t n) const;
    *bc- *fg- *jk- *no- *rs- *vw- Yz
  
    size_t find_first_of (char c, size_t pos = 0) const;
    *bc- *fg- *jk- *no- *rs- *vw- Y2

  (2)代码示例二：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba");
  
      cout<<"size_t find_first_of (const string& str, size_t pos = 0) const;"<<endl;
      string str2("aeimqu");
      size_t found1 = str1.find_first_of(str2);
      if (found1 != string::npos)
      {
          str1[found1]='*';
          //found1 = str1.find_first_of(str2, found1+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (const char* s, size_t pos = 0) const;"<<endl;
      size_t found2 = str1.find_first_of("dhlptxz");
      if (found2 != string::npos)
      {
          str1[found2]='-';
          //found2 = str1.find_first_of("dhlptx", found2+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_first_of("yz", 0, 1);
      if (found3 != string::npos)
      {
          str1[found3]='Y';
          //found3 = str1.find_first_of("yz", found3+1, 1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_of (char c, size_t pos = 0) const;"<<endl;
      size_t found4 = str1.find_first_of('z');
      if (found4 != string::npos)
      {
          str1[found4]='2';
          //found4 = str1.find_first_of("z", found4+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_first_of (const string& str, size_t pos = 0) const;
    *bcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_of (const char* s, size_t pos = 0) const;
    *bc- efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_of (const char* s, size_t pos, size_t n) const;
    *bc- efgh ijkl mnop qrst uvwx Yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_of (char c, size_t pos = 0) const;
    *bc- efgh ijkl mnop qrst uvwx Y2 zy xwvu tsrq ponm lkji hgfe dcba

1.3 std::string::find_first_not_of

• 原型：size_t find_first_not_of (const string& str, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符不在目标字符串str(string型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_first_not_of (const char* s, size_t pos = 0) const;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符不在目标字符串s(char型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_first_not_of (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos处，依此查找每个字符。如果某字符不在目标字符串s前n个字符(char型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_first_not_of (char c, size_t pos = 0) const noexcept;
• 说明：从源字符串起始位置pos(默认为0)处，依此查找每个字符。如果某字符不等于目标字符c，则返回首次不匹配的该字符的位置。
• 注意：如果没有找到不匹配的内容，则返回string::npos(从字符串的前端开始查找)

• 代码示例：

  (1)示例代码一：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz");
  
      cout<<"size_t find_first_not_of (const string& str, size_t pos = 0) const;"<<endl;
      string str2("bcd fgh jkl nop rst vwx yz");
      size_t found1 = str1.find_first_not_of(str2);
      while (found1 != string::npos)
      {
          str1[found1]='*';
          found1 = str1.find_first_not_of(str2, found1+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (const char* s, size_t pos = 0) const;"<<endl;
      size_t found2 = str1.find_first_not_of("abc efg ijk mno qrs uvw yz *");
      while (found2 != string::npos)
      {
          str1[found2]='-';
          found2 = str1.find_first_not_of("abc efg ijk mno qrs uvw yz *", found2+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_first_not_of("abcd efgh ijkl mnop qrst uvwx z * -", 0, strlen("abcd efgh ijkl mnop qrst uvwx z * -"));
      while (found3 != string::npos)
      {
          str1[found3]='Y';
          found3 = str1.find_first_not_of("abcd efgh ijkl mnop qrst uvwx z * -", found3+1, strlen("abcd efgh ijkl mnop qrst uvwx z * -"));
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (char c, size_t pos = 0) const;"<<endl;
      size_t found4 = str1.find_first_not_of('z', str1.size()-1);
      if (found4 == string::npos)
      {
          str1[str1.size()-1]='2';
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_first_of (const string& str, size_t pos = 0) const;
    *bcd *fgh *jkl *nop *rst *vwx yz
  
    size_t find_first_of (const char* s, size_t pos = 0) const;
    *bc- *fg- *jk- *no- *rs- *vw- yz
  
    size_t find_first_of (const char* s, size_t pos, size_t n) const;
    *bc- *fg- *jk- *no- *rs- *vw- Yz
  
    size_t find_first_of (char c, size_t pos = 0) const;
    *bc- *fg- *jk- *no- *rs- *vw- Y2

  (2)示例代码二：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba");
  
      cout<<"size_t find_first_not_of (const string& str, size_t pos = 0) const;"<<endl;
      string str2("bcd fgh jkl nop rst vwx yz");
      size_t found1 = str1.find_first_not_of(str2);
      if (found1 != string::npos)
      {
          str1[found1]='*';
          //found1 = str1.find_first_not_of(str2, found1+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (const char* s, size_t pos = 0) const;"<<endl;
      size_t found2 = str1.find_first_not_of("abc efg ijk mno qrs uvw yz *");
      if (found2 != string::npos)
      {
          str1[found2]='-';
          //found2 = str1.find_first_not_of("abc efg ijk mno qrs uvw yz *", found2+1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_first_not_of("abcd efgh ijkl mnop qrst uvwx z * -", 0, strlen("abcd efgh ijkl mnop qrst uvwx z * -"));
      if (found3 != string::npos)
      {
          str1[found3]='Y';
          //found3 = str1.find_first_not_of("abcd efgh ijkl mnop qrst uvwx z * -", found3+1, strlen("abcd efgh ijkl mnop qrst uvwx z * -"));
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_first_not_of (char c, size_t pos = 0) const;"<<endl;
      size_t found4 = str1.find_first_not_of('a', str1.size()-1);
      if (found4 == string::npos)
      {
          str1[str1.size()-1]='A';
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_first_not_of (const string& str, size_t pos = 0) const;
    *bcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_not_of (const char* s, size_t pos = 0) const;
    *bc- efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_not_of (const char* s, size_t pos, size_t n) const;
    *bc- efgh ijkl mnop qrst uvwx Yz zy xwvu tsrq ponm lkji hgfe dcba
  
    size_t find_first_not_of (char c, size_t pos = 0) const;
    *bc- efgh ijkl mnop qrst uvwx Yz zy xwvu tsrq ponm lkji hgfe dcbA

1.4 std::string::rfind

• 原型：size_t rfind (const string& str, size_t pos = npos) const noexcept;
• 说明：从源字符串起始位置pos(默认为npos)处，查找有目标字符串str(string型字符串)的位置。
• 原型：size_t rfind (const char* s, size_t pos = npos) const;
• 说明：从源字符串起始位置pos(默认为npos)处，查找有目标字符串s(char型字符串)的位置。
• 原型：size_t rfind (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos处，查找有目标字符串s前n个字符(char型字符串)的位置。
• 原型：size_t rfind (char c, size_t pos = npos) const noexcept;
• 说明：从源字符串起始位置pos(默认为npos)处，查找有目标字符c的位置。
• 注意：如果找到，则返回首次匹配的开始位置，如果没有找到匹配的内容，则返回string::npos(从字符串的末端开始查找)

• 代码示例：

  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("one two three four one two three four");
  
      cout<<"size_t rfind (const string& str, size_t pos = npos) const noexcept;"<<endl;
      string str2("one");
      size_t found1 = str1.rfind(str2);
      if (found1 != string::npos)
      {
          str1.replace(found1, str2.size(), "ONE");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t rfind (const char* s, size_t pos = npos) const;"<<endl;
      size_t found2 = str1.rfind("two");
      if (found2 != string::npos)
      {
          str1.replace(found2, strlen("two"), "TWO");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t rfind (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.rfind("three", string::npos, 5);
      if (found3 != string::npos)
      {
          str1.replace(found3, strlen("three"), "THREE");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t rfind (char c, size_t pos = npos) const noexcept;"<<endl;
      size_t found4 = str1.rfind('f');
      if (found4 != string::npos)
      {
          str1.replace(found4, sizeof('f'), "F");
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t rfind (const string& str, size_t pos = npos) const noexcept;
    one two three four ONE two three four
  
    size_t rfind (const char* s, size_t pos = npos) const;
    one two three four ONE TWO three four
  
    size_t rfind (const char* s, size_t pos, size_t n) const;
    one two three four ONE TWO THREE four
  
    size_t rfind (char c, size_t pos = npos) const noexcept;
    one two three four ONE TWO THREE Four

1.5 std::string::size_t find_last_of

• 原型：size_t find_last_of (const string& str, size_t pos = npos) const noexcept;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符在目标字符串str(string型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_last_of (const char* s, size_t pos = npos) const;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符在目标字符串s(char型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_last_of (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos处，依此查找每个字符。如果某字符在目标字符串s前n个字符(char型字符串)中，则返回首次匹配的该字符的位置。
• 原型：size_t find_last_of (char c, size_t pos = npos) const noexcept;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符等于目标字符c，则返回首次匹配的该字符的位置。
• 注意：如果没有找到匹配的内容，则返回string::npos(从字符串的末端开始查找)

• 代码示例：

  (1)代码示例一：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz");
  
      cout<<"size_t find_last_of (const string& str, size_t pos = npos) const;"<<endl;
      string str2("aeimqu");
      size_t found1 = str1.find_last_of(str2);
      while (found1 != string::npos)
      {
          str1[found1]='*';
          found1 = str1.find_last_of(str2, found1-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (const char* s, size_t pos = npos) const;"<<endl;
      size_t found2 = str1.find_last_of("dhlptx");
      while (found2 != string::npos)
      {
          str1[found2]='-';
          found2 = str1.find_last_of("dhlptx", found2-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_last_of("y", string::npos, 1);
      while (found3 != string::npos)
      {
          str1[found3]='Y';
          found3 = str1.find_last_of("y", found3-1, 1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (char c, size_t pos = npos) const;"<<endl;
      size_t found4 = str1.find_last_of('z');
      while (found4 != string::npos)
      {
          str1[found4]='2';
          found4 = str1.find_last_of("z", found4-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_last_of (const string& str, size_t pos = npos) const;
    *bcd *fgh *jkl *nop *rst *vwx yz
  
    size_t find_last_of (const char* s, size_t pos = npos) const;
    *bc- *fg- *jk- *no- *rs- *vw- yz
  
    size_t find_last_of (const char* s, size_t pos, size_t n) const;
    *bc- *fg- *jk- *no- *rs- *vw- Yz
  
    size_t find_last_of (char c, size_t pos = npos) const;
    *bc- *fg- *jk- *no- *rs- *vw- Y2

  (2)代码示例二：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba");
  
      cout<<"size_t find_last_of (const string& str, size_t pos = string::npos) const;"<<endl;
      string str2("aeimqu");
      size_t found1 = str1.find_last_of(str2);
      if (found1 != string::npos)
      {
          str1[found1]='*';
          //found1 = str1.find_last_of(str2, found1-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (const char* s, size_t pos = string::npos) const;"<<endl;
      size_t found2 = str1.find_last_of("dhlptxz");
      if (found2 != string::npos)
      {
          str1[found2]='-';
          //found2 = str1.find_last_of("dhlptx", found2-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_last_of("yz", string::npos, 1);
      if (found3 != string::npos)
      {
          str1[found3]='Y';
          //found3 = str1.find_last_of("yz", found3-1, 1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_of (char c, size_t pos = string::npos) const;"<<endl;
      size_t found4 = str1.find_last_of('z');
      if (found4 != string::npos)
      {
          str1[found4]='2';
          //found4 = str1.find_last_of("z", found4-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_last_of (const string& str, size_t pos = string::npos) const;
    abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcb*
  
    size_t find_last_of (const char* s, size_t pos = string::npos) const;
    abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe -cb*
  
    size_t find_last_of (const char* s, size_t pos, size_t n) const;
    abcd efgh ijkl mnop qrst uvwx yz zY xwvu tsrq ponm lkji hgfe -cb*
  
    size_t find_last_of (char c, size_t pos = string::npos) const;
    abcd efgh ijkl mnop qrst uvwx yz 2Y xwvu tsrq ponm lkji hgfe -cb*

1.6 std::string::find_last_not_of

• 原型：size_t find_last_not_of (const string& str, size_t pos = npos) const noexcept;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符不在目标字符串str(string型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_last_not_of (const char* s, size_t pos = npos) const;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符不在目标字符串s(char型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_first_not_of (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos处，依此查找每个字符。如果某字符不在目标字符串s前n个字符(char型字符串)中，则返回首次不匹配的该字符的位置。
• 原型：size_t find_last_not_of (const char* s, size_t pos, size_t n) const;
• 说明：从源字符串起始位置pos(默认为npos)处，依此查找每个字符。如果某字符不等于目标字符c，则返回首次不匹配的该字符的位置。
• 注意：如果没有找到不匹配的内容，则返回string::npos(从字符串的末端开始查找)

• 代码示例：

  (1)示例代码一：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz");
  
      cout<<"size_t find_last_not_of (const string& str, size_t pos = npos) const;"<<endl;
      string str2("bcd fgh jkl nop rst vwx yz *");
      size_t found1 = str1.find_last_not_of(str2);
      while (found1 != string::npos)
      {
          str1[found1]='*';
          found1 = str1.find_last_not_of(str2, found1-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (const char* s, size_t pos = npos) const;"<<endl;
      size_t found2 = str1.find_last_not_of("abc efg ijk mno qrs uvw yz * -");
      while (found2 != string::npos)
      {
          str1[found2]='-';
          found2 = str1.find_last_not_of("abc efg ijk mno qrs uvw yz * -", found2-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_last_not_of("abcd efgh ijkl mnop qrst uvwx z * - Y", string::npos, strlen("abcd efgh ijkl mnop qrst uvwx z * - Y"));
      while (found3 != string::npos)
      {
          str1[found3]='Y';
          found3 = str1.find_last_not_of("abcd efgh ijkl mnop qrst uvwx z * - Y", found3-1, strlen("abcd efgh ijkl mnop qrst uvwx z * - Y"));
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (char c, size_t pos = npos) const;"<<endl;
      size_t found4 = str1.find_last_not_of('2');
      if (found4 != string::npos)
      {
          str1[found4]='2';
          //found4 = str1.find_last_not_of('2', found4-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_last_not_of (const string& str, size_t pos = npos) const;
    *bcd *fgh *jkl *nop *rst *vwx yz
  
    size_t find_last_not_of (const char* s, size_t pos = npos) const;
    *bc- *fg- *jk- *no- *rs- *vw- yz
  
    size_t find_last_not_of (const char* s, size_t pos, size_t n) const;
    *bc- *fg- *jk- *no- *rs- *vw- Yz
  
    size_t find_last_not_of (char c, size_t pos = npos) const;
    *bc- *fg- *jk- *no- *rs- *vw- Y2

  (2)示例代码二：
  
  #include <iostream>
  
  
  #include <string>
  
  using namespace std;
  int main ()
  {
      string str1("abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcba");
  
      cout<<"size_t find_last_not_of (const string& str, size_t pos = npos) const;"<<endl;
      string str2("bcd fgh jkl nop rst vwx yz *");
      size_t found1 = str1.find_last_not_of(str2);
      if (found1 != string::npos)
      {
          str1[found1]='*';
          //found1 = str1.find_last_not_of(str2, found1-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (const char* s, size_t pos = npos) const;"<<endl;
      size_t found2 = str1.find_last_not_of("abc efg ijk mno qrs uvw yz * -");
      if (found2 != string::npos)
      {
          str1[found2]='-';
          //found2 = str1.find_last_not_of("abc efg ijk mno qrs uvw yz * -", found2-1);
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (const char* s, size_t pos, size_t n) const;"<<endl;
      size_t found3 = str1.find_last_not_of("abcd efgh ijkl mnop qrst uvwx z * - Y", string::npos, strlen("abcd efgh ijkl mnop qrst uvwx z * - Y"));
      if (found3 != string::npos)
      {
          str1[found3]='Y';
          //found3 = str1.find_last_not_of("abcd efgh ijkl mnop qrst uvwx z * - Y", found3-1, strlen("abcd efgh ijkl mnop qrst uvwx z * - Y"));
      }
      cout<<str1<<endl;
      cout<<endl;
  
      cout<<"size_t find_last_not_of (char c, size_t pos = npos) const;"<<endl;
      size_t found4 = str1.find_last_not_of('a', 0);
      if (found4 == string::npos)
      {
          str1[0]='A';
      }
      cout<<str1<<endl;
      cout<<endl;
  
      system("pause");
      return 0;
  }
  =>size_t find_last_not_of (const string& str, size_t pos = npos) const;
    abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe dcb*
  
    size_t find_last_not_of (const char* s, size_t pos = npos) const;
    abcd efgh ijkl mnop qrst uvwx yz zy xwvu tsrq ponm lkji hgfe -cb*
  
    size_t find_last_not_of (const char* s, size_t pos, size_t n) const;
    abcd efgh ijkl mnop qrst uvwx yz zY xwvu tsrq ponm lkji hgfe -cb*
  
    size_t find_last_not_of (char c, size_t pos = npos) const;
    Abcd efgh ijkl mnop qrst uvwx yz zY xwvu tsrq ponm lkji hgfe -cb*

参考文献：
[1] 网络资源：
http://www.cplusplus.com/reference/string/string/find/
http://www.cplusplus.com/reference/string/string/find_first_of/
http://www.cplusplus.com/reference/string/string/find_first_not_of/
http://www.cplusplus.com/reference/string/string/rfind/
http://www.cplusplus.com/reference/string/string/find_last_of/
http://www.cplusplus.com/reference/string/string/find_last_not_of/