This example uses the Hashtable type and instantiates it upon the managed heap. Then, three key-value pairs are added to the instance. Third, we use the foreach-loop construct to loop over the contents of the Hashtable instance.
Hashtable
Note This gives us a pair of values, encoded in a DictionaryEntry struct value.
Struct
Also To access the key and value of a DictionaryEntry, please use the named properties.
C# program that uses DictionaryEntry type and foreach
using System;
using System.Collections;
class Program
{
static void Main()
{
// Create hashtable with some keys and values.
Hashtable hashtable = new Hashtable();
hashtable.Add(1,
"one");
hashtable.Add(2,
"two");
hashtable.Add(3,
"three");
// Enumerate the hashtable.
foreach (
DictionaryEntry entry in hashtable)
{
Console.WriteLine(
"{0} = {1}", entry.Key, entry.Value);
}
}
}
3 = three
2 = two
1 = one
Discussion. DictionaryEntry is not tied to the Hashtable collection. You can create an instance to store a key-value pair anywhere. Because this type is a value type, it is copied onto the evaluation stack whenever used as a variable or parameter.
And The DictionaryEntry stores two object pointers, which are four bytes on 32-bit operating systems but eight bytes on 64-bit systems.
Summary. To loop over a Hashtable collection, then, you can use a foreach-loop construct and then access the properties on each DictionaryEntry. As with many associative collections, the looping order is undefined.
Value type The DictionaryEntry type, as a value type, does not incur the overhead of objects.
Further It can be instantiated anywhere in your program to store a pair of object references.