Lesson 31 - Creating Overloaded Methods

Tutorial Series: Free C# Fundamentals via ASP.NET Web Apps

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In this lesson, you will learn about overloaded methods. We have noted previously with Intellisense that some of the built-in helper methods that we’ve been using have several versions of the same method that you can choose from. You may also have noticed that these different versions are differentiated by the input parameters that they require and that in a nutshell is what overloaded methods are: several methods that share the same method name, yet have different input parameters and possibly have different implementation details as well.

Step 1: Create a New Project

To demonstrate method overloading, create a new ASP.NET project based on where we left off with the previous lesson and add three new methods to the code in Default.aspx.cs:


cs-asp-031---creating-overloaded-methods.001


Even at a quick glance, you will probably notice that these three methods have the same basic purpose – displaying stats and information about the monster. However they differ in the amount of information they output based on the input parameters provided.

Step 2: Understanding When to Overload Methods

The problem is that you, the programmer, have to remember the different names for these methods and know how to find them in Intellisense. This may not sound like a tremendous challenge at first. However, as an application grows it just adds to possible confusion and friction in the development process. To alleviate this, let’s simply overload these methods by naming them with the exact same identifier:


cs-asp-031---creating-overloaded-methods.002


Step 3: Distinguishing Between a Method’s Body and Signature

For this to compile properly, the .NET Framework needs to determine that these methods are separate despite sharing the same name. The way that it does this is by looking at the method signature, which is the set of “header information” prior to the method’s code block:


cs-asp-031---creating-overloaded-methods.003


This method signature is defined by:

  • Its accessibility level (private).

  • Its return type (void).

  • Its identifier (MethodSignature).

  • Its amount, and type, of parameters (object input1, object input2, object input3).

The input parameters are the only part of the method signature that the compiler uses to differentiate each method sharing the same name, yet still grouping them together as overloads of the same method. As long as the amount and the type of parameters used are different, it will be considered a valid overload (bear in mind that the input parameter names are not factored in):


cs-asp-031---creating-overloaded-methods.004


Step 4: Finding Available Overloads with Intellisense

Notice also how the third example has a different return type, as well as a different accessibility modifier. Since these elements of the method signature are not factors towards determining method overloading, they do not pose a problem and Intellisense will still group them together:


cs-asp-031---creating-overloaded-methods.005


Going back to the project, you can now try to call displayMonsterStats() and with the up/down arrow keys you can cycle through the variations available to you:


cs-asp-031---creating-overloaded-methods.006


cs-asp-031---creating-overloaded-methods.007


cs-asp-031---creating-overloaded-methods.008


Tip:

Overloaded methods are particularly useful when you’re writing code that may be used by another developer to create their own code. Consider how useful it has been for you, the consumer/developer of the .NET library, to be able to use Intellisense and see how many variations of methods are available to you with Int.Parse(), Random.Next(), String.Format(), etc.


Related Articles in this Tutorial:

Lesson 1 - Series Introduction

Lesson 2 - Installing Visual Studio 2015

Lesson 3 - Building Your First Web App

Lesson 4 - Understanding What You Just Did

Lesson 5 - Working with Projects in Visual Studio

Lesson 6 - Simple Web Page Formatting in Visual Studio

Challenge 1

Solution 1

Lesson 7 - Variables and Data Types

Lesson 8 - Data Type Conversion

Lesson 9 - Arithmetic Operators

Lesson 10 - C# Syntax Basics

Challenge 2 - ChallengeSimpleCalculator

Solution - ChallengeSimpleCalculator

Lesson 11 - Conditional If Statements

Lesson 12 - The Conditional Ternary Operator

Challenge 3 - ChallengeConditionalRadioButton

Solution - Challenge Conditional RadioButton

Lesson 13 - Comparison and Logical Operators

Lesson 13 Challenge - First Papa Bob's Website

Solution - Challenge First Papa Bob's Website

Lesson 14 - Working with Dates and Times

Lesson 15 - Working With Spans of Time

Lesson 16 - Working with the Calendar Server Control

Challenge 4 - Challenge Days Between Dates

Solution - Challenge Days Between Dates

Lesson 17 - Page_Load and Page.IsPostBack

Lesson 18 - Setting a Break Point and Debugging

Lesson 19 - Formatting Strings

Challenge 5 - Challenge Epic Spies Assignment

Solution - Challenge Epic Spies Assignment

Lesson 20 - Maintaining State with ViewState

Lesson 21 - Storing Values in Arrays

Lesson 22 - Understanding Multidimensional Arrays

Lesson 23 - Changing the Length of an Array

Challenge 6 - Challenge Epic Spies Asset Tracker

Solution - Challenge Epic Spies Asset Tracker

Lesson 24 - Understanding Variable Scope

Lesson 25 - Code Blocks and Nested If Statements

Lesson 26 - Looping with the For Iteration Statement

Challenge 7 - Challenge For Xmen Battle Count

Solution - Challenge For Xmen Battle Count

Lesson 27 - Looping with the while() & do...while() Iteration Statements

Lesson 28 - Creating and Calling Simple Helper Methods

Lesson 29 - Creating Methods with Input Parameters

Lesson 30 - Returning Values from Methods

Lesson 31 - Creating Overloaded Methods

Lesson 32 - Creating Optional Parameters

Lesson 33 - Creating Names Parameters

Lesson 34 - Creating Methods with Output Parameters

Challenge 8 - Challenge Postal Calculator Helper Methods

Solution - Challenge Postal Calculator Helper Methods

Mega Challenge Casino

Solution - Mega Challenge Casino

Lesson 35 - Manipulating Strings

Challenge 9 - Phun With Strings

Solution - Challenge Phun With Strings

Lesson 36 - Introduction to Classes and Objects

Challenge - Hero Monster Classes Part 1

Solution - Hero Monster Classes Part 1

Challenge - Hero Monster Classes Part 2

Solution - Challenge Hero Monster Classes Part 2

Lesson 37 - Creating Class Files Creating Cohesive Classes and Code Navigation

Lesson 38 - Understanding Object References and Object Lifetime

Lesson 39 - Understanding the .NET Framework and Compilation

Lesson 40 - Namespaces and Using Directives

Lesson 41 - Creating Class Libraries and Adding References to Assemblies

Lesson 42 - Accessibility Modifiers, Fields and Properties

Lesson 43 - Creating Constructor Methods

Lesson 44 - Naming Conventions for Identifiers

Lesson 45 - Static vs Instance Members

Challenge 10 - Challenge Simple Darts

Solution - Challenge Simple Darts

Lesson 46 - Working with the List Collection

Lesson 47 - Object Initializers

Lesson 48 - Collection Initializers

Lesson 49 - Working with the Dictionary Collection

Lesson 50 - Looping with the foreach Iteration Statement

Lesson 51 - Implicitly-Typed Variables with the var Keyword

Challenge 11 - Challenge Student Courses

Solution - Challenge Student Courses

Mega Challenge War

Solution - Mega Challenge War

Lesson 52 - Creating GUIDs

Lesson 53 - Working with Enumerations

Lesson 54 - Understanding the switch() Statement

Lesson 55 - First Pass at the Separation of Concerns Principle

Lesson 56 - Understanding Exception Handling

Lesson 57 - Understanding Global Exception Handling

Lesson 58 - Understanding Custom Exceptions

Lesson 59 - Creating a Database in Visual Studio

Lesson 60 - Creating an Entity Data Model

Lesson 61 - Displaying the DbSet Result in an ASP.NET GridView

Lesson 62 - Implementing a Button Command in a GridView

Lesson 63 - Using a Tools-Centric Approach to Building a Database Application

Lesson 64 - Using a Maintenance-Driven Approach to Building a Database Application

Lesson 65 - Creating a New Instance of an Entity and Persisting it to the Database

Lesson 66 - Package Management with NuGet

Lesson 67 - NuGet No-Commit Workflow

Lesson 68 - Introduction the Twitter Bootstrap CSS Framework

Lesson 69 - Mapping Enum Types to Entity Properties in the Framework Designer

Lesson 70 - Deploying the App to Microsoft Azure Web Services Web Apps

Papa Bob's Mega Challenge

Papa Bob's Mega Solution Part 1 - Setting up the Solution

Papa Bob's Mega Solution Part 2 - Adding an Order to the Database

Papa Bob's Mega Solution Part 3 - Passing an Order from the Presentation Layer

Papa Bob's Mega Solution Part 4 - Creating the Order Form

Papa Bob's Mega Solution Part 5 - Adding Enums

Papa Bob's Mega Solution Part 6 - Creating an Order with Validation

Papa Bob's Mega Solution Part 7 - Calculating the Order Price

Papa Bob's Mega Solution Part 8 - Displaying the Price to the User

Papa Bob's Mega Solution Part 9 - Creating the Order Management Page


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