방법: 문자열 컬렉션 결합 및 비교(LINQ)
업데이트: 2007년 11월
이 예제에서는 텍스트 줄이 포함된 파일을 병합한 다음 결과를 정렬하는 방법을 보여 줍니다. 특히 두 개의 텍스트 줄 집합에서의 간단한 연결, 공용 구조체 및 교집합을 수행하는 방법을 보여 줍니다.
프로젝트 및 텍스트 파일을 설정하려면
이러한 이름을 names1.txt라는 텍스트 파일에 복사하고 해당 텍스트 파일을 솔루션 폴더에 저장합니다.
Bankov, Peter Holm, Michael Garcia, Hugo Potra, Cristina Noriega, Fabricio Aw, Kam Foo Beebe, Ann Toyoshima, Tim Guy, Wey Yuan Garcia, Debra이러한 이름을 names2.txt라는 텍스트 파일에 복사하고 해당 텍스트 파일을 솔루션 폴더에 저장합니다. 두 파일에 공통된 이름이 몇 개 있습니다.
Liu, Jinghao Bankov, Peter Holm, Michael Garcia, Hugo Beebe, Ann Gilchrist, Beth Myrcha, Jacek Giakoumakis, Leo McLin, Nkenge El Yassir, Mehdi
예제
Class ConcatenateStrings
Shared Sub Main()
' Create the IEnumerable data sources.
Dim fileA As String() = System.IO.File.ReadAllLines("../../../names1.txt")
Dim fileB As String() = System.IO.File.ReadAllLines("../../../names2.txt")
' Simple concatenation and sort.
Dim concatQuery = fileA.Concat(fileB).OrderBy(Function(name) name)
' Pass the query variable to another function for execution
OutputQueryResults(concatQuery, "Simple concatenation and sort. Duplicates are preserved:")
' New query. Concatenate files and remove duplicates
Dim uniqueNamesQuery = fileA.Union(fileB).OrderBy(Function(name) name)
OutputQueryResults(uniqueNamesQuery, "Union removes duplicate names:")
' New query. Find the names that occur in both files.
Dim commonNamesQuery = fileA.Intersect(fileB)
OutputQueryResults(commonNamesQuery, "Merge based on intersect: ")
' New query in three steps for better readability
' First filter each list separately
Dim nameToSearch As String = "Garcia"
Dim mergeQueryA As IEnumerable(Of String) = From name In fileA _
Let n = name.Split(New Char() {","}) _
Where n(0) = nameToSearch _
Select name
Dim mergeQueryB = From name In fileB _
Let n = name.Split(New Char() {","}) _
Where n(0) = nameToSearch _
Select name
' Create a new query to concatenate and sort results. Duplicates are removed in Union.
' Note that none of the queries actually executed until the call to OutputQueryResults.
Dim mergeSortQuery = mergeQueryA.Union(mergeQueryB).OrderBy(Function(str) str)
' Now execute mergeSortQuery
OutputQueryResults(mergeSortQuery, "Concat based on partial name match """ & nameToSearch & """ from each list:")
' Keep console window open in debug mode.
Console.WriteLine("Press any key to exit.")
Console.ReadKey()
End Sub
Shared Sub OutputQueryResults(ByVal query As IEnumerable(Of String), ByVal message As String)
Console.WriteLine(System.Environment.NewLine & message)
For Each item As String In query
Console.WriteLine(item)
Next
Console.WriteLine(query.Count & " total names in list")
End Sub
End Class
' Output:
' Simple concatenation and sort. Duplicates are preserved:
' Aw, Kam Foo
' Bankov, Peter
' Bankov, Peter
' Beebe, Ann
' Beebe, Ann
' El Yassir, Mehdi
' Garcia, Debra
' Garcia, Hugo
' Garcia, Hugo
' Giakoumakis, Leo
' Gilchrist, Beth
' Guy, Wey Yuan
' Holm, Michael
' Holm, Michael
' Liu, Jinghao
' McLin, Nkenge
' Myrcha, Jacek
' Noriega, Fabricio
' Potra, Cristina
' Toyoshima, Tim
' 20 total names in list
' Union removes duplicate names:
' Aw, Kam Foo
' Bankov, Peter
' Beebe, Ann
' El Yassir, Mehdi
' Garcia, Debra
' Garcia, Hugo
' Giakoumakis, Leo
' Gilchrist, Beth
' Guy, Wey Yuan
' Holm, Michael
' Liu, Jinghao
' McLin, Nkenge
' Myrcha, Jacek
' Noriega, Fabricio
' Potra, Cristina
' Toyoshima, Tim
' 16 total names in list
' Merge based on intersect:
' Bankov, Peter
' Holm, Michael
' Garcia, Hugo
' Beebe, Ann
' 4 total names in list
' Concat based on partial name match "Garcia" from each list:
' Garcia, Debra
' Garcia, Hugo
' 2 total names in list
class MergeStrings
{
static void Main(string[] args)
{
//Put text files in your solution folder
string[] fileA = System.IO.File.ReadAllLines(@"../../../names1.txt");
string[] fileB = System.IO.File.ReadAllLines(@"../../../names2.txt");
//Simple concatenation and sort. Duplicates are preserved.
IEnumerable<string> concatQuery =
fileA.Concat(fileB).OrderBy(s => s);
// Pass the query variable to another function for execution.
OutputQueryResults(concatQuery, "Simple concatenate and sort. Duplicates are preserved:");
// Concatenate and remove duplicate names based on
// default string comparer.
IEnumerable<string> uniqueNamesQuery =
fileA.Union(fileB).OrderBy(s => s);
OutputQueryResults(uniqueNamesQuery, "Union removes duplicate names:");
// Find the names that occur in both files (based on
// default string comparer).
IEnumerable<string> commonNamesQuery =
fileA.Intersect(fileB);
OutputQueryResults(commonNamesQuery, "Merge based on intersect:");
// Find the matching fields in each list. Merge the two
// results by using Concat, and then
// sort using the default string comparer.
string nameMatch = "Garcia";
IEnumerable<String> tempQuery1 =
from name in fileA
let n = name.Split(',')
where n[0] == nameMatch
select name;
IEnumerable<string> tempQuery2 =
from name2 in fileB
let n2 = name2.Split(',')
where n2[0] == nameMatch
select name2;
IEnumerable<string> nameMatchQuery =
tempQuery1.Concat(tempQuery2).OrderBy(s => s);
OutputQueryResults(nameMatchQuery, String.Format("Concat based on partial name match \"{0}\":", nameMatch));
// Keep the console window open in debug mode.
Console.WriteLine("Press any key to exit");
Console.ReadKey();
}
static void OutputQueryResults(IEnumerable<string> query, string message)
{
Console.WriteLine(System.Environment.NewLine + message);
foreach (string item in query)
{
Console.WriteLine(item);
}
Console.WriteLine("{0} total names in list", query.Count());
}
}
/* Output:
Simple concatenate and sort. Duplicates are preserved:
Aw, Kam Foo
Bankov, Peter
Bankov, Peter
Beebe, Ann
Beebe, Ann
El Yassir, Mehdi
Garcia, Debra
Garcia, Hugo
Garcia, Hugo
Giakoumakis, Leo
Gilchrist, Beth
Guy, Wey Yuan
Holm, Michael
Holm, Michael
Liu, Jinghao
McLin, Nkenge
Myrcha, Jacek
Noriega, Fabricio
Potra, Cristina
Toyoshima, Tim
20 total names in list
Union removes duplicate names:
Aw, Kam Foo
Bankov, Peter
Beebe, Ann
El Yassir, Mehdi
Garcia, Debra
Garcia, Hugo
Giakoumakis, Leo
Gilchrist, Beth
Guy, Wey Yuan
Holm, Michael
Liu, Jinghao
McLin, Nkenge
Myrcha, Jacek
Noriega, Fabricio
Potra, Cristina
Toyoshima, Tim
16 total names in list
Merge based on intersect:
Bankov, Peter
Holm, Michael
Garcia, Hugo
Beebe, Ann
4 total names in list
Concat based on partial name match "Garcia":
Garcia, Debra
Garcia, Hugo
Garcia, Hugo
3 total names in list
*/
코드 컴파일
.NET Framework 버전 3.5를 대상으로 하는 Visual Studio 프로젝트를 만듭니다. 기본적으로 프로젝트에는 System.Core.dll에 대한 참조 및 System.Linq 네임스페이스에 대한 using 지시문(C#) 또는 Imports 문(Visual Basic)이 있습니다. C# 프로젝트에서는 System.IO 네임스페이스에 대한 using 지시문을 추가합니다.
프로젝트에 이 코드를 복사합니다.
F5 키를 눌러 프로그램을 컴파일하고 실행합니다.
아무 키나 눌러 콘솔 창을 닫습니다.