Usage of Hashtable in C #

Name space

System.Collections

Name

Hash table (Hashtable)

Describe

A key-value pair that handles and behaves like KeyValue, where key is usually used for quick lookups, while key is case-sensitive, and value is used to store values corresponding to key. KeyValue Key-value pairs in Hashtable are all object types, so hashtable can support any type of KeyValue key-value pair.

Second, the simple operation of the hash table

Hashtable hshtable = new Hashtable (); Create a hash table
Hshtable.  ADD ("Person1", "ZHANGHF"); Add a key-value pair to the hash table
Hshtable.  Clear (); Remove all key-value pairs from the hash table
Hshtable.   Contains ("Person1"); Determines whether the hash table contains the key
String name = (string) hshtable["Person1"]. ToString (); Takes the value of the specified key in the hash table
Hshtable.remove ("Person1"); Deletes the key value pair for the specified key in the hash table
IDictionaryEnumerator en = Hshtable.getenumerator (); Iterate through all the keys of the hash table and read out the corresponding values
while (en. MoveNext ())
{
String str = en. Value.tostring ();
}

The following console program will contain all of the above actions:

123456789Ten One A - - the - - - + - + A at - - - - - in - to + - the * $Panax Notoginseng - the + A the + - $ $ - - the -Wuyi the

class Program    {        static void Main(string[] args)        {            // 创建一个Hashtable实例            Hashtable ht=new Hashtable();              // 添加keyvalue键值对            ht.Add("A","1");            ht.Add("B","2");            ht.Add("C","3");            ht.Add("D","4");             // 遍历哈希表            foreach (DictionaryEntry de in ht)            {                Console.WriteLine("Key -- {0}; Value --{1}.", de.Key, de.Value);            }             // 哈希表排序            ArrayList akeys=new ArrayList(ht.Keys);             akeys.Sort();            foreach (string skey in akeys)             {                Console.WriteLine("{0, -15} {1, -15}", skey, ht[skey]);             }             // 判断哈希表是否包含特定键,其返回值为true或false            if (ht.Contains("A"))              Console.WriteLine(ht["A"]);                         // 给对应的键赋值            ht["A"] ="你好";             // 移除一个keyvalue键值对            ht.Remove("C");             // 遍历哈希表            foreach (DictionaryEntry de in ht)            {                Console.WriteLine("Key -- {0}; Value --{1}.", de.Key, de.Value);            }                    // 移除所有元素            ht.Clear();               // 此处将不会有任何输出            Console.WriteLine(ht["A"]);            Console.ReadKey();        }    }

Usage of Hashtable in C #