C# Sorted List (How it Works for Developers)

What is a SortedList?

The C# SortedList class is a collection of key-value pairs, similar to a dictionary, but it has the added benefit of automatic sorting by keys. It is part of the System.Collections.Generic namespace and is designed for scenarios where you need quick access to sorted data. SortedList<TKey, TValue> is ideal when you need to maintain data in a particular order and access elements efficiently by key.

When working with SortedLists alongside PDF generation tasks, IronPDF integrates perfectly with this class, providing enhanced control over PDF generation.

Key Features and Use Cases

• Key-Value Pair Storage: Like a dictionary, SortedList stores data as key-value pairs.
• Automatic Sorting: SortedList keeps associated values sorted by key in ascending order by default.
• Efficient Data Retrieval: Quick retrieval of associated values by key makes it suitable for lookups.
• Use Cases: Useful for applications needing sorted data, such as managing ordered lists of names, dates, or numerical values.

Data Structure Overview

The public class SortedList is a hybrid between an array and a hash table and organizes its items by key. Internally, it uses a sorted array to keep key values in order, ensuring efficient lookups by key. However, insertion and deletion operations can be slower than in a Dictionary.

Sorting Mechanism

By default, SortedList<TKey, TValue> sorts keys in ascending order using the IComparable interface, which ensures that string keys and other types implement a default comparison behavior. If a custom sorting order is needed, a custom comparer can be provided.

Advantages and Limitations

• Pros:
  • Fast Key Access: Provides fast O(log n) access by key.
  • Sorted Order: Data is automatically sorted by key without additional sorting overhead.
• Cons:
  • Insertion Speed: Slower than Dictionary for insertions, especially with large data sizes.
  • Limited Efficiency for Non-Key Operations: Less efficient in scenarios where data isn’t accessed primarily by specific key values.

Creating a SortedList

You can create a SortedList in C# using either the default constructor or by passing an IComparer if custom sorting is needed. The SortedList has a default initial capacity of 16, which can be adjusted for performance improvements when the approximate size is known.

// Create a SortedList with integer keys and string values
SortedList<int, string> sortedList = new SortedList<int, string>();

// Create a SortedList with integer keys and string values
SortedList<int, string> sortedList = new SortedList<int, string>();

Adding Items

Add key-value pairs to the SortedList using the Add method. This keeps items sorted by key. The following code keeps the SortedList data in ascending order of keys.

sortedList.Add(1, "Apple");
sortedList.Add(3, "Banana");
sortedList.Add(2, "Cherry");

sortedList.Add(1, "Apple");
sortedList.Add(3, "Banana");
sortedList.Add(2, "Cherry");

Accessing and Modifying Elements

Access elements in a SortedList by their keys. You can retrieve or modify values associated with keys directly.

// Accessing a specific value by key
string value = sortedList[1];  // Retrieves "Apple"
// Modifying a value
sortedList[1] = "Avocado";   // Changes the value associated with key 1 to "Avocado"

// Accessing a specific value by key
string value = sortedList[1];  // Retrieves "Apple"
// Modifying a value
sortedList[1] = "Avocado";   // Changes the value associated with key 1 to "Avocado"

Removing Items

Remove items using specific keys with the Remove method or using the specified index with RemoveAt. Both allow controlled deletion of objects from the SortedList.

sortedList.Remove(3);       // Removes the entry with key 3
sortedList.RemoveAt(0);     // Removes the entry at the zero-based index 0

sortedList.Remove(3);       // Removes the entry with key 3
sortedList.RemoveAt(0);     // Removes the entry at the zero-based index 0

Iterating Over a SortedList

Iterate over SortedList using a foreach loop to retrieve both keys and values in sorted order.

foreach (KeyValuePair<int, string> kvp in sortedList)
{
    Console.WriteLine($"Key: {kvp.Key}, Value: {kvp.Value}");
}

foreach (KeyValuePair<int, string> kvp in sortedList)
{
    Console.WriteLine($"Key: {kvp.Key}, Value: {kvp.Value}");
}

Comparing SortedList with Dictionary and List

• SortedList vs. Dictionary: SortedList is slower for insertions compared to Dictionary due to sorting overhead.
• SortedList vs. List: Unlike a list, SortedList is designed for accessing elements by key and maintaining sorted order.

When to Use SortedList: Use it when you need sorted data and primarily access it by key, especially for read-heavy scenarios.

Introduction to IronPDF

IronPDF is a powerful library for generating and modifying PDF files in C#. It allows developers to create PDFs from various sources, add content programmatically, and customize PDF layouts. In this section, we’ll use IronPDF to create a PDF report from SortedList data.

Generating PDF Reports from SortedList Data

To begin using IronPDF, install the IronPDF NuGet package:

Install-Package IronPdf

Example: Exporting Data from a SortedList to a PDF

The following example demonstrates how to export data from a SortedList to a PDF table.

First, set up your SortedList:

SortedList<int, string> sortedList = new SortedList<int, string>
{
    { 1, "Apple" },
    { 2, "Banana" },
    { 3, "Cherry" }
};

SortedList<int, string> sortedList = new SortedList<int, string>
{
    { 1, "Apple" },
    { 2, "Banana" },
    { 3, "Cherry" }
};

Next, use IronPDF to generate a PDF from this data:

// Initialize a PDF renderer
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Build HTML string with table format
string html = "<h1>Sorted List Data</h1><table border='1'><tr><th>Key</th><th>Value</th></tr>";
foreach (var kvp in sortedList)
{
    html += $"<tr><td>{kvp.Key}</td><td>{kvp.Value}</td></tr>";
}
html += "</table>";

// Render HTML to PDF and save it
PdfDocument pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("sortedList.pdf");

// Initialize a PDF renderer
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Build HTML string with table format
string html = "<h1>Sorted List Data</h1><table border='1'><tr><th>Key</th><th>Value</th></tr>";
foreach (var kvp in sortedList)
{
    html += $"<tr><td>{kvp.Key}</td><td>{kvp.Value}</td></tr>";
}
html += "</table>";

// Render HTML to PDF and save it
PdfDocument pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("sortedList.pdf");

This code creates an HTML table from the SortedList data and converts it into a PDF using IronPDF.

Advanced Features

• Customizing PDF Layout: IronPDF allows CSS styling for layouts, fonts, colors, etc.
• Headers and Footers: IronPDF supports headers and footers, which can include page numbers or logos.