{"id":374,"date":"2023-08-03T06:00:40","date_gmt":"2023-08-03T06:00:40","guid":{"rendered":"http:\/\/192.168.0.142\/?p=374"},"modified":"2023-08-03T07:16:28","modified_gmt":"2023-08-03T07:16:28","slug":"difference-between-hashtable-and-dictionary-in-c","status":"publish","type":"post","link":"http:\/\/192.168.0.142\/difference-between-hashtable-and-dictionary-in-c\/","title":{"rendered":"Difference between Hashtable and Dictionary in C#"},"content":{"rendered":"\n<ul>\n<li>&nbsp;A HashTable or Dictionary is a data structure that stores key-value pairs.<\/li>\n\n\n\n<li>Both implement the IDictionary interface.<\/li>\n\n\n\n<li>The Dictionary generic class also implements the IDictionary generic interface.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Hashtable<\/h3>\n\n\n\n<ul>\n<li>Hashtable optimizes lookups. It computes a hash of each key you add. It then uses this hash code to look up the element very quickly. It\u2019s an older .NET framework type. It\u2019s slower than the generic Dictionary type.<\/li>\n\n\n\n<li>It returns null if we try to find a key which does not exist.<\/li>\n\n\n\n<li>It is slower than dictionary because it requires boxing and unboxing<\/li>\n\n\n\n<li>Hashtable is not a generic type.<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"csharp\" class=\"language-csharp\">  Hashtable hashtable = new Hashtable();\n  hashtable.Add(\"Area\", 1000);\n  int value = (int)hashtable[\"Area\"];<\/code><\/pre>\n\n\n\n<ul>\n<li>A Hashtable object consists of buckets that contain the elements of the collection.&nbsp; A bucket is a virtual subgroup of elements within the Hashtable, which makes searching and retrieving easier and faster than in most collections.<\/li>\n\n\n\n<li>Each bucket is associated with a hash code, generated using a hash function and based on the key of the element.<\/li>\n\n\n\n<li>&nbsp;When an object is added to a Hashtable, it is stored in the bucket that is associated with the hash code that matches the object&#8217;s hash code. When a value is being searched for in the Hashtable, the hash code is generated for that value, and the bucket associated with that hash code is searched.<\/li>\n\n\n\n<li>A Hash table is made up of a mapping function and an array.<\/li>\n\n\n\n<li>The array contains your data, while the mapping function is used to assign numerical&nbsp; values(keys) to the data.<\/li>\n\n\n\n<li>This helps in categorizing the data, which speeds up search times when you search for it.<\/li>\n\n\n\n<li>A hash function should assign unique keys to each bucket (data slot), but in practice a pair of keys might get hashed to the same table. This is known as a hash collision, and the design of the hash table must be able to take this probability into account.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Dictionary<\/h3>\n\n\n\n<ul>\n<li>A dictionary is used where fast lookups are critical. The Dictionary type provides fast lookups with keys to get values.<\/li>\n\n\n\n<li>It returns error if we try to find a key which does not exist.<\/li>\n\n\n\n<li>It is faster than a Hashtable because there is no boxing and unboxing.<\/li>\n\n\n\n<li>Dictionary is a generic type which means we can use it with any data type.<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"csharp\" class=\"language-csharp\"> Dictionary&lt;string, int&gt; d = new Dictionary&lt;string, int&gt;();\n   foreach (KeyValuePair&lt;string, int&gt; pair in d)\n           {\n               Console.WriteLine (\"{0}, {1}\",pair.Key,  pair.Value);\n           }\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Hashtable Dictionary<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[33,36,35],"_links":{"self":[{"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/posts\/374"}],"collection":[{"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/comments?post=374"}],"version-history":[{"count":5,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/posts\/374\/revisions"}],"predecessor-version":[{"id":425,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/posts\/374\/revisions\/425"}],"wp:attachment":[{"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/media?parent=374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/categories?post=374"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/192.168.0.142\/wp-json\/wp\/v2\/tags?post=374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}