C# | Gets or sets the value at the specified key in StringDictionary
StringDictionary.Item[String] Property is used to get or set the value associated with the specified key.
Syntax:
public virtual string this[string key] { get; set; }
Here, key is the Key of type System.String whose value is be to get or set.
Return Value: This property returns the value associated with the specified key. If the specified key is not found, Get returns null, and Set creates a new entry with the specified key.
Exception: This property throws ArgumentNullException
if the key is null.
Below programs illustrate the use of above-discussed property:
Example 1:
// C# code to get or set the value at // the specified key in StringDictionary using System; using System.Collections; using System.Collections.Specialized; class GFG { // Driver code public static void Main() { // Creating a StringDictionary named my1 StringDictionary my1 = new StringDictionary(); // Adding key and value into the StringDictionary my1.Add( "1" , "C" ); my1.Add( "2" , "C++" ); my1.Add( "3" , "Java" ); my1.Add( "4" , "Python" ); my1.Add( "5" , "C#" ); // Displaying the keys and // values in StringDictionary foreach (DictionaryEntry d in my1) { Console.WriteLine(d.Key + " " + d.Value); } Console.WriteLine( "\nAfter Item[String] Property: \n" ); // setting the value at key 2 my1[ "2" ] = "HTML" ; // Displaying the keys and // values in StringDictionary foreach (DictionaryEntry d1 in my1) { Console.WriteLine(d1.Key + " " + d1.Value); } } } |
Output:
3 Java 5 C# 4 Python 2 C++ 1 C After Item[String] Property: 3 Java 4 Python 2 HTML 1 C 5 C#
Example 2:
// C# code to get or set the value at // the specified key in StringDictionary using System; using System.Collections; using System.Collections.Specialized; class GFG { // Driver code public static void Main() { // Creating a StringDictionary named my1 StringDictionary my1 = new StringDictionary(); // Adding key and value into the StringDictionary my1.Add( "1" , "HTML" ); my1.Add( "2" , "CSS" ); my1.Add( "3" , "PHP" ); my1.Add( "4" , "MongoDB" ); my1.Add( "5" , "AngularJS" ); // Displaying the keys and // values in StringDictionary foreach (DictionaryEntry d in my1) { Console.WriteLine(d.Key + " " + d.Value); } Console.WriteLine( "\nAfter Item[String] Property: \n" ); // setting the value at Key 8 // here key 8 is not present // so it will add a new key/value // pair. see output my1[ "8" ] = "C#" ; // Displaying the keys and // values in StringDictionary foreach (DictionaryEntry d1 in my1) { Console.WriteLine(d1.Key + " " + d1.Value); } } } |
Output:
3 PHP 5 AngularJS 4 MongoDB 2 CSS 1 HTML After Item[String] Property: 3 PHP 4 MongoDB 2 CSS 1 HTML 8 C# 5 AngularJS
Reference:
- https://docs.microsoft.com/en-us/dotnet/api/system.collections.specialized.stringdictionary.item?view=netframework-4.7.2
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