C# Program to find a key in Dictionary

Firstly, set a Dictionary collection with elements.

Dictionary<int, string> d = new Dictionary<int, string>() {    {1,"Applianes"},    {2, "Clothing"},    {3,"Toys"},    {4,"Footwear"},    {5, "Accessories"} };

Now, let’s say you need to check whether key 5 exists or not. For that, use ContainsKey() method. It returns True if key is found.

d.ContainsKey(5);

Let us see the complete code.

Example

 Live Demo

using System; using System.Collections.Generic; public class Program {    public static void Main() {       Dictionary<int, string> d = new Dictionary<int, string>() {          {1,"Electronics"},          {2, "Clothing"},          {3,"Toys"},          {4,"Footwear"},          {5, "Accessories"}       };       foreach (KeyValuePair<int, string> ele in d) {          Console.WriteLine("Key = {0}, Value = {1}", ele.Key, ele.Value);       }       Console.WriteLine("Key 5 exists? "+d.ContainsKey(5));    } }

Output

Key = 1, Value = Electronics Key = 2, Value = Clothing Key = 3, Value = Toys Key = 4, Value = Footwear Key = 5, Value = Accessories Key 5 exists? True