Guide to Creating Custom Types in Go

Table of Contents

  1. Introduction
  2. Prerequisites
  3. Custom Types Overview
  4. Creating a Custom Type
  5. Using a Custom Type
  6. Summary

Introduction

In Go, custom types allow us to define new types based on existing ones or create completely new types to suit our specific needs. This flexibility enables us to write more expressive and maintainable code by encapsulating related behavior and properties.

This tutorial will guide you step-by-step in creating and using custom types in Go. By the end of this tutorial, you will understand how to define custom types, their underlying data types, and utilize them effectively in your code.

Prerequisites

Before diving into custom types, it is assumed that you have a basic understanding of Go syntax and have Go installed on your machine. If you need help setting up Go, please refer to the official documentation for your specific platform.

Custom Types Overview

Custom types in Go are created using the type keyword followed by the new type name, and the underlying data type. They provide a way to define more descriptive types and can be used to create abstractions and improve code readability. Custom types can be created based on built-in types or other custom types.

For example, let’s consider a scenario where we need to work with temperatures in our code. We can define a custom type Temperature based on the built-in float64 type to represent temperatures more accurately:

type Temperature float64

Here, Temperature is a new type that behaves like a float64, but it provides us with the ability to add additional functions, methods, and constraints specific to temperatures.

Creating a Custom Type

To create a custom type in Go, follow these steps:

  1. Choose an appropriate name for your custom type. It should be descriptive and convey its purpose.

  2. Use the type keyword followed by the new type name.

  3. Specify the underlying data type the new type will be based on.

    Let’s create a custom type called Person based on the struct type to represent a person’s information:

     type Person struct {
     Name string
     Age  int
 }

    In this example, Person is a new type based on a struct that contains two fields: Name of type string and Age of type int. Now we can create variables of type Person to store and manipulate person-related data more intuitively.

Using a Custom Type

Once we have defined a custom type, we can declare variables of that type and utilize them throughout our codebase.

func main() {
    person := Person{
        Name: "John",
        Age:  30,
    }

    fmt.Println("Name:", person.Name)
    fmt.Println("Age:", person.Age)
}

In this example, we create a variable person of type Person and assign it a name of “John” and an age of 30. We can access the fields of the Person struct using the dot notation (person.Name, person.Age), just like accessing fields of any other struct.

Summary

In this tutorial, we learned about creating custom types in Go. We explored how to define a custom type based on an existing type using the type keyword. We also saw how to create a custom type based on a struct and use it to store and manipulate related data.

Creating custom types allows us to write more expressive and maintainable code by encapsulating behavior and properties specific to our domain. It improves code readability and enables us to create abstractions that make our code more modular and reusable.

Now that you have a good understanding of creating custom types in Go, you can apply this knowledge in your own projects to represent and manipulate data more effectively.

Happy coding!

In this tutorial, we covered the following categories: Syntax and Basics, Functions and Packages.

Published:

Related Articles