C# | Check if the StringDictionary contains a specific value

Last Updated : 01 Feb, 2019

StringDictionary.ContainsValue(String) method is used to check whether the StringDictionary contains a specific value or not.

Syntax:

public virtual bool ContainsValue (string value);

Here, value is the value to locate in the StringDictionary. The value can be null.

Return Value: The method returns true if the StringDictionary contains an element with the specified value, otherwise it returns false.

Below programs illustrate the use of StringDictionary.ContainsValue(String) method:

Example 1:

// C# code to check if the 
// StringDictionary contains 
// a specific value 
using System; 
using System.Collections; 
using System.Collections.Specialized; 
  
class GFG { 
  
// Driver code 
public static void Main() 
{ 
  
    // Creating a StringDictionary named myDict 
    StringDictionary myDict = new StringDictionary(); 
  
    // Adding key and value into the StringDictionary 
    myDict.Add("G", "Geeks"); 
    myDict.Add("F", "For"); 
    myDict.Add("C", "C++"); 
    myDict.Add("DS", "Data Structures"); 
    myDict.Add("N", "Noida"); 
  
    // Checking if "C++" is contained in 
    // StringDictionary myDict 
    if (myDict.ContainsValue("C++")) 
        Console.WriteLine("StringDictionary myDict contains the value"); 
    else
        Console.WriteLine("StringDictionary myDict does not contain the value"); 
    } 
} 

Output:

StringDictionary myDict contains the value

Example 2:

// C# code to check if the 
// StringDictionary contains 
// a specific value 
using System; 
using System.Collections; 
using System.Collections.Specialized; 
  
class GFG { 
  
// Driver code 
public static void Main() 
{ 
  
    // Creating a StringDictionary named myDict 
    StringDictionary myDict = new StringDictionary(); 
  
    // Adding key and value into the StringDictionary 
    myDict.Add("G", "Geeks"); 
    myDict.Add("F", "For"); 
    myDict.Add("C", "C++"); 
    myDict.Add("DS", "Data Structures"); 
    myDict.Add("N", "Noida"); 
  
    // Checking if "null" is contained in 
    // StringDictionary myDict 
    // It should not raise any exception 
    if (myDict.ContainsValue(null)) 
        Console.WriteLine("StringDictionary myDict contains the value"); 
    else
        Console.WriteLine("StringDictionary myDict does not contain the value"); 
    } 
} 

Output:

StringDictionary myDict does not contain the value

Note:

The values of the elements of the StringDictionary are compared to the specified value using the Object.Equals method.
This method is an O(n) operation, where n is Count.

Reference: