C# | Dictionary.Keys Property
This property is used to get a collection containing the keys in the Dictionary.
Syntax:
public System.Collections.Generic.Dictionary<TKey, TValue>.KeyCollection Keys { get; }
Return Value : It returns a collection containing the keys in the Dictionary.
Below are the programs to illustrate the use of above-discussed property:
Example 1:
// C# code to get the keys // in the Dictionary using System; using System.Collections.Generic; class GFG { // Driver code public static void Main() { // Create a new dictionary of // strings, with string keys. Dictionary< string , string > myDict = new Dictionary< string , string >(); // Adding key/value pairs in myDict myDict.Add( "Australia" , "Canberra" ); myDict.Add( "Belgium" , "Brussels" ); myDict.Add( "Netherlands" , "Amsterdam" ); myDict.Add( "China" , "Beijing" ); myDict.Add( "Russia" , "Moscow" ); myDict.Add( "India" , "New Delhi" ); // To get count of key/value pairs in myDict Console.WriteLine( "Total key/value pairs" + " in myDict are : " + myDict.Count); // To get the keys alone, // use the Keys property. Dictionary< string , string >.KeyCollection keyColl = myDict.Keys; // The elements of the KeyCollection // are strongly typed with the type // that was specified for dictionary // keys foreach ( string s in keyColl) { Console.WriteLine( "Key = {0}" , s); } } } |
Output:
Total key/value pairs in myDict are : 6 Key = Australia Key = Belgium Key = Netherlands Key = China Key = Russia Key = India
Example 2:
// C# code to get the keys in the Dictionary using System; using System.Collections.Generic; class GFG { // Driver code public static void Main() { // Create a new dictionary of // strings, with string keys. Dictionary< int , int > myDict = new Dictionary< int , int >(); // Adding key/value pairs in myDict myDict.Add(9, 8); myDict.Add(3, 4); myDict.Add(4, 7); myDict.Add(1, 7); // To get count of key/value pairs in myDict Console.WriteLine( "Total key/value pairs " + "in myDict are : " + myDict.Count); // To get the keys alone, // use the Keys property. Dictionary< int , int >.KeyCollection keyColl = myDict.Keys; // The elements of the KeyCollection // are strongly typed with the type // that was specified for dictionary keys. foreach ( int s in keyColl) { Console.WriteLine( "Key = {0}" , s); } } } |
Output:
Total key/value pairs in myDict are : 4 Key = 9 Key = 3 Key = 4 Key = 1
Reference:
- https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.dictionary-2.keys?view=netframework-4.7.2
Contact Us