检查哈希表是否在C#中包含特定的键
要检查Hashtable是否包含特定密钥，代码如下-
示例
using System;
using System.Collections;
public class Demo {
public static void Main() public static void Main(){
Hashtable hash = new Hashtable();
hash.Add("One", "Katie");
hash.Add("Two", "John");
hash.Add("Three", "Barry");
hash.Add("Four", "Mark");
hash.Add("Five","Harry");
hash.Add("Six", "Nathan");
hash.Add("Seven", "Tom");
hash.Add("Eight","Andy");
hash.Add("Nine", "Illeana");
hash.Add("Ten", "Tim");
Console.WriteLine("Hashtable Key and Value pairs...");
foreach(DictionaryEntry entry in hash){
Console.WriteLine("{0} and {1} ", entry.Key, entry.Value);
}
Console.WriteLine("Is Hashtable having fixed size? = "+hash.IsFixedSize);
Console.WriteLine("If Hashtable read-only? = "+hash.IsReadOnly);
Console.WriteLine("The Hashtable consists of the key? = "+hash.ContainsKey("Seven"));
}
}输出结果
这将产生以下输出-
Hashtable Key and Value pairs... One and Katie Ten and Tim Five and Harry Three and Barry Seven and Tom Two and John Four and Mark Eight and Andy Nine and Illeana Six and Nathan Is Hashtable having fixed size? = False If Hashtable read-only? = False The Hashtable consists of the key? = True
示例
让我们看另一个例子-
using System;
using System.Collections;
public class Demo {
public static void Main(){
Hashtable hash = new Hashtable();
hash.Add("1", "A");
hash.Add("2", "B");
hash.Add("3", "C");
hash.Add("4", "D");
hash.Add("5","E");
hash.Add("6", "F");
hash.Add("7", "G");
hash.Add("8","H");
hash.Add("9", "I");
hash.Add("10", "J");
Console.WriteLine("Hashtable Key and Value pairs...");
foreach(DictionaryEntry entry in hash){
Console.WriteLine("{0} and {1} ", entry.Key, entry.Value);
}
Console.WriteLine("Is Hashtable having fixed size? = "+hash.IsFixedSize);
Console.WriteLine("If Hashtable read-only? = "+hash.IsReadOnly);
Console.WriteLine("The Hashtable consists of the key? = "+hash.ContainsKey("5"));
}
}输出结果
这将产生以下输出-
Hashtable Key and Value pairs... 10 and J 1 and A 2 and B 3 and C 4 and D 5 and E 6 and F 7 and G 8 and H 9 and I Is Hashtable having fixed size? = False If Hashtable read-only? = False The Hashtable consists of the key? = True