Hashtable.ContainsKey 메서드

아티클
08/21/2007

Hashtable에 특정 키가 들어 있는지 여부를 확인합니다.

네임스페이스: System.Collections
어셈블리: mscorlib(mscorlib.dll)

구문

‘선언
Public Overridable Function ContainsKey ( _
    key As Object _
) As Boolean
‘사용 방법
Dim instance As Hashtable
Dim key As Object
Dim returnValue As Boolean

returnValue = instance.ContainsKey(key)

public virtual bool ContainsKey (
    Object key
)

public:
virtual bool ContainsKey (
    Object^ key
)

public boolean ContainsKey (
    Object key
)

public function ContainsKey (
    key : Object
) : boolean

매개 변수

key
Hashtable에서 찾을 수 있는 키입니다.

반환 값

Hashtable에 지정된 키가 있는 요소가 포함되어 있으면 true이고, 그렇지 않으면 false입니다.

예외

예외 형식	조건
ArgumentNullException	key가 Null 참조(Visual Basic의 경우 Nothing)인 경우

설명

이 메서드는 Contains와 동일하게 동작합니다.

이 메서드는 O(1) 연산입니다.

예제

다음 예제에서는 Hashtable에 특정 요소가 포함되어 있는지 여부를 확인하는 방법을 설명합니다.

Imports System
Imports System.Collections

Public Class SamplesHashtable

    Public Shared Sub Main()

        ' Creates and initializes a new Hashtable.
        Dim myHT As New Hashtable()
        myHT.Add(0, "zero")
        myHT.Add(1, "one")
        myHT.Add(2, "two")
        myHT.Add(3, "three")
        myHT.Add(4, "four")

        ' Displays the values of the Hashtable.
        Console.WriteLine("The Hashtable contains the following values:")
        PrintIndexAndKeysAndValues(myHT)

        ' Searches for a specific key.
        Dim myKey As Integer = 2
        Console.Write("The key ""{0}"" is ", myKey)
        If(myHT.ContainsKey(myKey))
           Console.WriteLine("in the Hashtable.")
        Else
           Console.WriteLine("NOT in the Hashtable.")
        End If

        myKey = 6
        Console.Write("The key ""{0}"" is ", myKey)
        If(myHT.ContainsKey(myKey))
           Console.WriteLine(" in the Hashtable.")
        Else
           Console.WriteLine(" NOT in the Hashtable.")
        End If

        ' Searches for a specific value.
        Dim myValue As String = "three"
        Console.Write("The value ""{0}"" is ", myValue)
        If(myHT.ContainsValue(myValue))
           Console.WriteLine(" in the Hashtable.")
        Else
           Console.WriteLine(" NOT in the Hashtable.")
        End If

        myValue = "nine"
        Console.Write("The value ""{0}"" is ", myValue)
        If(myHT.ContainsValue(myValue))
           Console.WriteLine(" in the Hashtable.")
        Else
           Console.WriteLine(" NOT in the Hashtable.")
        End If

    End Sub 'Main

    Public Shared Sub PrintIndexAndKeysAndValues(myHT As Hashtable)
        Dim i As Integer = 0
        Console.WriteLine(vbTab + "-INDEX-" + vbTab + "-KEY-" + vbTab + "-VALUE-")
        Dim de As DictionaryEntry
        For Each de In  myHT
            Console.WriteLine(vbTab + "[{0}]:" + vbTab + "{1}" + vbTab + "{2}", i, de.Key, de.Value)
            i = i + 1
        Next de
        Console.WriteLine()
    End Sub 'PrintIndexAndKeysAndValues

End Class 'SamplesHashtable 


' This code produces the following output.
' 
' The Hashtable contains the following values:
'         -INDEX- -KEY-   -VALUE-
'         [0]:    4       four
'         [1]:    3       three
'         [2]:    2       two
'         [3]:    1       one
'         [4]:    0       zero
'
' The key "2" is in the Hashtable.
' The key "6" is NOT in the Hashtable.
' The value "three" is in the Hashtable.
' The value "nine" is NOT in the Hashtable.

using System;
using System.Collections;
public class SamplesHashtable  {

   public static void Main()  {

      // Creates and initializes a new Hashtable.
      Hashtable myHT = new Hashtable();
      myHT.Add( 0, "zero" );
      myHT.Add( 1, "one" );
      myHT.Add( 2, "two" );
      myHT.Add( 3, "three" );
      myHT.Add( 4, "four" );

      // Displays the values of the Hashtable.
      Console.WriteLine( "The Hashtable contains the following values:" );
      PrintIndexAndKeysAndValues( myHT );

      // Searches for a specific key.
      int myKey = 2;
      Console.WriteLine( "The key \"{0}\" is {1}.", myKey, myHT.ContainsKey( myKey ) ? "in the Hashtable" : "NOT in the Hashtable" );
      myKey = 6;
      Console.WriteLine( "The key \"{0}\" is {1}.", myKey, myHT.ContainsKey( myKey ) ? "in the Hashtable" : "NOT in the Hashtable" );

      // Searches for a specific value.
      String myValue = "three";
      Console.WriteLine( "The value \"{0}\" is {1}.", myValue, myHT.ContainsValue( myValue ) ? "in the Hashtable" : "NOT in the Hashtable" );
      myValue = "nine";
      Console.WriteLine( "The value \"{0}\" is {1}.", myValue, myHT.ContainsValue( myValue ) ? "in the Hashtable" : "NOT in the Hashtable" );
   }


   public static void PrintIndexAndKeysAndValues( Hashtable myHT )  {
      int i = 0;
      Console.WriteLine( "\t-INDEX-\t-KEY-\t-VALUE-" );
      foreach ( DictionaryEntry de in myHT )
         Console.WriteLine( "\t[{0}]:\t{1}\t{2}", i++, de.Key, de.Value );
      Console.WriteLine();
   }

}


/* 
This code produces the following output.

The Hashtable contains the following values:
        -INDEX- -KEY-   -VALUE-
        [0]:    4       four
        [1]:    3       three
        [2]:    2       two
        [3]:    1       one
        [4]:    0       zero

The key "2" is in the Hashtable.
The key "6" is NOT in the Hashtable.
The value "three" is in the Hashtable.
The value "nine" is NOT in the Hashtable.

*/

using namespace System;
using namespace System::Collections;
void PrintIndexAndKeysAndValues( Hashtable^ myHT );
int main()
{
   
   // Creates and initializes a new Hashtable.
   Hashtable^ myHT = gcnew Hashtable;
   myHT->Add( (int^)0, "zero" );
   myHT->Add( 1, "one" );
   myHT->Add( 2, "two" );
   myHT->Add( 3, "three" );
   myHT->Add( 4, "four" );
   
   // Displays the values of the Hashtable.
   Console::WriteLine( "The Hashtable contains the following values:" );
   PrintIndexAndKeysAndValues( myHT );
   
   // Searches for a specific key.
   int myKey = 2;
   Console::WriteLine( "The key \"{0}\" is {1}.", myKey, myHT->ContainsKey( myKey ) ? (String^)"in the Hashtable" : "NOT in the Hashtable" );
   myKey = 6;
   Console::WriteLine( "The key \"{0}\" is {1}.", myKey, myHT->ContainsKey( myKey ) ? (String^)"in the Hashtable" : "NOT in the Hashtable" );
   
   // Searches for a specific value.
   String^ myValue = "three";
   Console::WriteLine( "The value \"{0}\" is {1}.", myValue, myHT->ContainsValue( myValue ) ? (String^)"in the Hashtable" : "NOT in the Hashtable" );
   myValue = "nine";
   Console::WriteLine( "The value \"{0}\" is {1}.", myValue, myHT->ContainsValue( myValue ) ? (String^)"in the Hashtable" : "NOT in the Hashtable" );
}

void PrintIndexAndKeysAndValues( Hashtable^ myHT )
{
   int i = 0;
   Console::WriteLine( "\t-INDEX-\t-KEY-\t-VALUE-" );
   IEnumerator^ myEnum = myHT->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      DictionaryEntry de =  *safe_cast<DictionaryEntry ^>(myEnum->Current);
      Console::WriteLine( "\t[{0}]:\t{1}\t{2}", i++, de.Key, de.Value );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 The Hashtable contains the following values:
         -INDEX- -KEY-   -VALUE-
         [0]:    4       four
         [1]:    3       three
         [2]:    2       two
         [3]:    1       one
         [4]:    0       zero

 The key "2" is in the Hashtable.
 The key "6" is NOT in the Hashtable.
 The value "three" is in the Hashtable.
 The value "nine" is NOT in the Hashtable.

 */

import System.*;
import System.Collections.*;

public class SamplesHashtable
{
    public static void main(String[] args)
    {
        // Creates and initializes a new Hashtable.
        Hashtable myHT = new Hashtable();

        myHT.Add(new Integer(0), "zero");
        myHT.Add(new Integer(1), "one");
        myHT.Add(new Integer(2), "two");
        myHT.Add(new Integer(3), "three");
        myHT.Add(new Integer(4), "four");

        // Displays the values of the Hashtable.
        Console.WriteLine("The Hashtable contains the following values:");
        PrintIndexAndKeysAndValues(myHT);

        // Searches for a specific key.
        int myKey = 2;

        Console.WriteLine("The key \"{0}\" is {1}.", 
            System.Convert.ToString(myKey), 
            (myHT.ContainsKey(new Integer(myKey))) ? 
            "in the Hashtable" : "NOT in the Hashtable");
        myKey = 6;
        Console.WriteLine("The key \"{0}\" is {1}.", 
            System.Convert.ToString(myKey), 
            (myHT.ContainsKey(new Integer(myKey))) ? 
            "in the Hashtable" : "NOT in the Hashtable");

        // Searches for a specific value.
        String myValue = "three";

        Console.WriteLine("The value \"{0}\" is {1}.", myValue, 
            (myHT.ContainsValue(myValue)) ? 
            "in the Hashtable" : "NOT in the Hashtable");
        myValue = "nine";
        Console.WriteLine("The value \"{0}\" is {1}.", myValue, 
            (myHT.ContainsValue(myValue)) ? 
            "in the Hashtable" : "NOT in the Hashtable");
    } //main

    public static void PrintIndexAndKeysAndValues(Hashtable myHT)
    {
        int i = 0;
        Console.WriteLine("\t-INDEX-\t-KEY-\t-VALUE-");
        IEnumerator myEnumerator = myHT.GetEnumerator();

        while (myEnumerator.MoveNext()) {
            DictionaryEntry de = (DictionaryEntry)myEnumerator.get_Current();
            Console.WriteLine("\t[{0}]:\t{1}\t{2}", 
                System.Convert.ToString(i++), 
                de.get_Key().toString(), de.get_Value().toString());
        }
        Console.WriteLine();
    } //PrintIndexAndKeysAndValues
} //SamplesHashtable 

/* 
 This code produces the following output.
 
 The Hashtable contains the following values:
         -INDEX- -KEY-   -VALUE-
         [0]:    4       four
         [1]:    3       three
         [2]:    2       two
         [3]:    1       one
         [4]:    0       zero

 The key "2" is in the Hashtable.
 The key "6" is NOT in the Hashtable.
 The value "three" is in the Hashtable.
 The value "nine" is NOT in the Hashtable.
 */

import System
import System.Collections
import Microsoft.VisualBasic

// Creates and initializes a new Hashtable.
var myHT : Hashtable = new Hashtable()
myHT.Add(0, "zero")
myHT.Add(1, "one")
myHT.Add(2, "two")
myHT.Add(3, "three")
myHT.Add(4, "four")

// Displays the values of the Hashtable.
Console.WriteLine("The Hashtable contains the following values:")
PrintIndexAndKeysAndValues(myHT)

// Searches for a specific key.
var msg : String
var myKey : int = 2
if(myHT.ContainsKey(myKey))
    msg = "in the Hashtable"
else
    msg = "NOT in the Hashtable"
Console.WriteLine("The key \"{0}\" is {1}.", myKey, msg)
myKey = 6
if(myHT.ContainsKey(myKey))
    msg = "in the Hashtable"
else
    msg = "NOT in the Hashtable"
Console.WriteLine("The key \"{0}\" is {1}.", myKey, msg)

// Searches for a specific value.
var myValue : String = "three"
if(myHT.ContainsValue(myValue))
    msg = "in the Hashtable"
else
    msg = "NOT in the Hashtable"
Console.WriteLine("The value \"{0}\" is {1}.", myValue, msg)
myValue = "nine"
if(myHT.ContainsValue(myValue))
    msg = "in the Hashtable"
else
    msg = "NOT in the Hashtable"
Console.WriteLine("The value \"{0}\" is {1}.", myValue, msg)

function PrintIndexAndKeysAndValues(myList : Hashtable){
    var myEnumerator : IDictionaryEnumerator = myList.GetEnumerator()
    var i : int = 0
    Console.WriteLine("\t-INDEX-\t-KEY-\t-VALUE-")
    while(myEnumerator.MoveNext()){
        Console.WriteLine("\t[{0}]:\t{1}\t{2}", i++, myEnumerator.Key,
            myEnumerator.Value)
    }
    Console.WriteLine()
}

// This code produces the following output.
// 
// The Hashtable contains the following values:
//     -INDEX-    -KEY-    -VALUE-
//     [0]:       4        four
//     [1]:       3        three
//     [2]:       2        two
//     [3]:       1        one
//     [4]:       0        zero
// 
// The key "2" is in the Hashtable.
// The key "6" is NOT in the Hashtable.
// The value "three" is in the Hashtable.
// The value "nine" is NOT in the Hashtable.

플랫폼

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework에서 모든 플래폼의 모든 버전을 지원하지는 않습니다. 지원되는 버전의 목록은 시스템 요구 사항을 참조하십시오.

버전 정보

.NET Framework

2.0, 1.1, 1.0에서 지원

.NET Compact Framework

2.0, 1.0에서 지원

참고 항목

참조

Hashtable 클래스
Hashtable 멤버
System.Collections 네임스페이스
Contains
ContainsValue

다음을 통해 공유