Dictionary is used to represent a collection of key and Value pair of data. It is a generic class and it can store any data type. It came with .net F/W 2.0.
Dictionary contains key and value together as shown in given example below
protected void Page_Load(object sender, EventArgs e) { Dictionary<string, int> Emps = new Dictionary<string, int>(); Emps.Add("Ram", 1); Emps.Add("Mohan", 2); Emps.Add("Hari", 3); foreach (var name in Emps) { lblmsg.Text += name.Key + " " + name.Value +"<br>"; } }
Then output will come like this
Ram 1
Mohan 2
Hari 3
ContainKey and ContainValue Method
It has containkey and ContainValue method. Using ContainKey we can find the specific key in dictionary and using ContainValue we can get the specific value. It returns the Boolean value.
if(Emps.ContainsKey("Hari")) { int value = Emps["Hari"]; lblmsg.Text = value.ToString(); }
It has also add,remove and Clear method.
Advantages
1. Dictionary type provides fast lookups with keys to get values.
2. It stores any datatype
3. It provide good performance as compare to HashTable