C# | Search in a SortedList object

SortedList class is a collection of (key, value) pairs which are sorted according to keys. Those pairs can be accessible by key and as well as by index(zero-based indexing). This comes under System.Collections namespace. SortedList.ContainsKey(Object) method is used to check whether a SortedList object contains a specific key or not.

Properties:

A SortedList element can be accessed by its key or by its index.
A SortedList object internally maintains two arrays to store the elements of the list, i.e, one array for the keys and another array for the associated values.
A key cannot be null, but a value can be.
The capacity of a SortedList object is the number of elements the SortedList can hold.
A SortedList does not allow duplicate keys.
Operations on a SortedList object tend to be slower than operations on a Hashtable object because of the sorting.
Elements in this collection can be accessed using an integer index. Indexes in this collection are zero-based.

Syntax:

public virtual bool ContainsKey (object key);

Here, key is the key to locate in the SortedList object.

Return Value: This method will return True if the SortedList object contains an element with the specified key otherwise it returns False.

Exceptions:

ArgumentNullException : If the key is null.
InvalidOperationException : If the comparer throws an exception.

Below given are some examples to understand the implementation in a better way:

Example 1:

// C# code to check if a SortedList 
// object contains a specific key 

using System; 

using System.Collections; 

class GFG { 

    // Driver code 

    public static void Main() 

    { 

        // Creating an SortedList 

        SortedList mySortedList = new SortedList(); 

        // Adding elements to SortedList 

        mySortedList.Add("h", "Hello"); 

        mySortedList.Add("g", "Geeks"); 

        mySortedList.Add("f", "For"); 

        mySortedList.Add("n", "Noida"); 

        // Checking if a SortedList object 

        // contains a specific key 

        Console.WriteLine(mySortedList.ContainsKey("g")); 

    } 
}

Output:

True

Example 2:

// C# code to check if a SortedList 
// object contains a specific key 

using System; 

using System.Collections; 

class GFG { 

    // Driver code 

    public static void Main() 

    { 

        // Creating an SortedList 

        SortedList mySortedList = new SortedList(); 

        // Adding elements to SortedList 

        mySortedList.Add("h", "Hello"); 

        mySortedList.Add("g", "Geeks"); 

        mySortedList.Add("f", "For"); 

        mySortedList.Add("n", "Noida"); 

        // Checking if a SortedList object 

        // contains a specific key 

        // It should throw ArgumentNullException 

        // as the Key can not be null 

        Console.WriteLine(mySortedList.ContainsKey(null)); 

    } 
}