basic_string::find_first_of
指定された文字列の要素と一致する最初の文字を文字列で検索します。
size_type find_first_of(
value_type _Ch,
size_type _Off = 0
) const;
size_type find_first_of(
const value_type* _Ptr,
size_type _Off = 0
) const;
size_type find_first_of(
const value_type* _Ptr,
size_type _Off,
size_type _Count
) const;
size_type find_first_of(
const basic_string<CharType, Traits, Allocator>& _Str,
size_type _Off = 0
) const;
パラメーター
_Ch
メンバー関数が検索される文字値。_Off
検索を開始する位置のインデックス。_Ptr
メンバー関数が検索される C 文字列。_Count
メンバー関数が検索される C 文字列で、最初の文字から順方向に数えた文字数。_Str
メンバー関数が検索される文字列。
戻り値
成功した場合、検索する部分文字列の最初の文字のインデックス、それ以外の場合 npos。
使用例
// basic_string_find_first_of.cpp
// compile with: /EHsc
#include <string>
#include <iostream>
int main( )
{
using namespace std;
// The first member function
// searches for a single character in a string
string str1 ( "abcd-1234-abcd-1234" );
cout << "The original string str1 is: " << str1 << endl;
basic_string <char>::size_type indexCh1a, indexCh1b;
static const basic_string <char>::size_type npos = -1;
indexCh1a = str1.find_first_of ( "d" , 5 );
if ( indexCh1a != npos )
cout << "The index of the 1st 'd' found after the 5th"
<< " position in str1 is: " << indexCh1a << endl;
else
cout << "The character 'd' was not found in str1 ." << endl;
indexCh1b = str1.find_first_of ( "x" );
if ( indexCh1b != npos )
cout << "The index of the 'x' found in str1 is: "
<< indexCh1b << endl << endl;
else
cout << "The character 'x' was not found in str1."
<< endl << endl;
// The second member function searches a string
// for any element of a substring as specified by a C-string
string str2 ( "ABCD-1234-ABCD-1234" );
cout << "The original string str2 is: " << str2 << endl;
basic_string <char>::size_type indexCh2a, indexCh2b;
const char *cstr2 = "B1";
indexCh2a = str2.find_first_of ( cstr2 , 6 );
if ( indexCh2a != npos )
cout << "The index of the 1st occurrence of an "
<< "element of 'B1' in str2 after\n the 6th "
<< "position is: " << indexCh2a << endl;
else
cout << "Elements of the substring 'B1' were not "
<< "found in str2 after the 10th position."
<< endl;
const char *cstr2b = "D2";
indexCh2b = str2.find_first_of ( cstr2b );
if ( indexCh2b != npos )
cout << "The index of the 1st element of 'D2' "
<< "after\n the 0th position in str2 is: "
<< indexCh2b << endl << endl;
else
cout << "The substring 'D2' was not found in str2 ."
<< endl << endl << endl;
// The third member function searches a string
// for any element of a substring as specified by a C-string
string str3 ( "123-abc-123-abc-456-EFG-456-EFG" );
cout << "The original string str3 is: " << str3 << endl;
basic_string <char>::size_type indexCh3a, indexCh3b;
const char *cstr3a = "5G";
indexCh3a = str3.find_first_of ( cstr3a );
if ( indexCh3a != npos )
cout << "The index of the 1st occurrence of an "
<< "element of '5G' in str3 after\n the 0th "
<< "position is: " << indexCh3a << endl;
else
cout << "Elements of the substring '5G' were not "
<< "found in str3\n after the 0th position."
<< endl;
const char *cstr3b = "5GF";
indexCh3b = str3.find_first_of ( cstr3b , indexCh3a + 1 , 2 );
if (indexCh3b != npos )
cout << "The index of the second occurrence of an "
<< "element of '5G' in str3\n after the 0th "
<< "position is: " << indexCh3b << endl << endl;
else
cout << "Elements of the substring '5G' were not "
<< "found in str3\n after the first occurrrence."
<< endl << endl;
// The fourth member function searches a string
// for any element of a substring as specified by a string
string str4 ( "12-ab-12-ab" );
cout << "The original string str4 is: " << str4 << endl;
basic_string <char>::size_type indexCh4a, indexCh4b;
string str4a ( "ba3" );
indexCh4a = str4.find_first_of ( str4a , 5 );
if ( indexCh4a != npos )
cout << "The index of the 1st occurrence of an "
<< "element of 'ba3' in str4 after\n the 5th "
<< "position is: " << indexCh4a << endl;
else
cout << "Elements of the substring 'ba3' were not "
<< "found in str4\n after the 0th position."
<< endl;
string str4b ( "a2" );
indexCh4b = str4.find_first_of ( str4b );
if ( indexCh4b != npos )
cout << "The index of the 1st occurrence of an "
<< "element of 'a2' in str4 after\n the 0th "
<< "position is: " << indexCh4b << endl;
else
cout << "Elements of the substring 'a2' were not "
<< "found in str4\n after the 0th position."
<< endl;
}
必要条件
ヘッダー: の <文字列>
名前空間: std
参照
関連項目
basic_string::find_first_of (STL のサンプル)