Efficiently Clearing C#'s `SortedDictionary`: Removing All Key-Value Pairs with `Clear()`

Learn how to use C#'s `SortedDictionary.Clear()` method to efficiently remove all key-value pairs from a `SortedDictionary`. This tutorial explains its functionality, demonstrates its usage, and highlights its importance in managing and resetting `SortedDictionary` objects.

Understanding and Using `SortedDictionary.Clear()` in C#

Introduction

In C#, a `SortedDictionary` is a collection that stores key-value pairs, keeping the keys sorted in ascending order. The `Clear()` method provides a way to efficiently remove all elements from the `SortedDictionary`.

What is a `SortedDictionary`?

A `SortedDictionary` (found in the `System.Collections.Generic` namespace) is a dynamic collection. This means its size adjusts automatically as you add or remove items. Key characteristics include:

• Unique Keys: Keys must be unique; duplicates are not allowed.
• Immutable Keys: Keys cannot be changed after they are added.
• Null Keys: Keys cannot be null.
• Null Values: Values can be null (if the value type is a reference type).
• Fast Inserts and Deletes: `SortedDictionary` is optimized for efficient addition and removal of elements.
• Homogeneous Key-Value Pairs: Keys and values must be of the same type.

`SortedDictionary.Clear()` Method

The `Clear()` method removes all key-value pairs from the `SortedDictionary`. After calling `Clear()`, the dictionary is empty.

Method Signature

public void Clear();

Example 1: Clearing a String-Based `SortedDictionary`

using System;
using System.Collections.Generic;

class SortedDictionaryClear {
    public static void Main() {
        SortedDictionary<string, string> dict = new SortedDictionary<string, string>();
        dict.Add("Afghanistan", "Kabul");
        dict.Add("Sri Lanka", "Colombo");
        // ... add more key-value pairs ...

        Console.WriteLine($"Initial count: {dict.Count}"); // Output: 8
        dict.Clear();
        Console.WriteLine($"Count after Clear(): {dict.Count}"); // Output: 0
    }
}

Example 2: Clearing an Integer-Based `SortedDictionary`

using System;
using System.Collections.Generic;

class SortedDictionaryClear {
    public static void Main() {
        SortedDictionary<int, int> dict = new SortedDictionary<int, int>();
        dict.Add(1, 11);
        dict.Add(2, 22);
        // ... add more key-value pairs ...

        Console.WriteLine($"Initial count: {dict.Count}"); // Output: 9
        dict.Clear();
        Console.WriteLine($"Count after Clear(): {dict.Count}"); // Output: 0
    }
}

Conclusion

The `SortedDictionary.Clear()` method provides a straightforward way to empty a `SortedDictionary`. This is useful when you need to reset the dictionary or reuse it for a new set of key-value pairs.