Data Dictionary in c#

1)How to declare data Dictionary:

 Dictionary<key, value> mydictionary = new Dictionary<key, value>();

-> Dictionary can be of any data type combination. ex: int, float,string
->First item in the dictionary will be a key and second item will be a value


2)How to add value to dictionary:
mydictionary.Add(key, value);




3)How  to retrieve values and keys from the dictionary:

foreach (KeyValuePair<key, value> item in  mydictionary)
{
                    string key = item.Key;
                    string val = item.Value;
                    string outputfile = outputfile + key+"\n"+val;
 }





4)How to search an item in dictionary
for a value:
mydictionary.ContainsValue(value);



for a key:
mydictionary.ContainsKey( key);





5)To clear value  from the dictionary
mydictionary.Clear();



Example:
 Dictionary<string, string> dictionary = new Dictionary<string, string>();
string a="Hello";
string b="World";
dictionary.Add(a, b);



 foreach (KeyValuePair<string, string> item in dictionary)
 {
                    string key = item.Key;
                    string val = item.Value;
                    outputfile = outputfile + "\n" + "\n" + "." + key + "\n" + "{" + "\n" + val;
  }