Types of Design Patterns and How To Implement One (With Example)

Design patterns are design level solutions for recurring problems that we software engineers come across often. It’s not code – I repeat, ❌CODE. It is like a description on how to tackle these problems and design a solution.

Using these patterns is considered good practice, as the design of the solution is quite tried and tested, resulting in higher readability of the final code. Design patterns are quite often created for and used by OOP Languages, like Java, in which most of the examples from here on will be written.

1. Creational: These patterns are designed for class instantiation. They can be either class-creation patterns or object-creational patterns.

2. Structural: These patterns are designed with regard to a classs structure and composition. The main goal of most of these patterns is to increase the functionality of the class(es) involved, without changing much of its composition.

10 Design Patterns Explained in 10 Minutes

Who uses design patterns?

Professionals with the following job titles can use design patterns to fix issues in their code:

What are design patterns?

Design patterns are solutions to common software issues in software design. However, design patterns arent portions of code. Rather, professionals who create software and programs can use these patterns as a template to write high-quality code. Because a design pattern isnt code, you can use them to write programs in multiple languages, including Java, C++ and Python. Here are elements design patterns share:

What are the benefits of using design patterns?

Design patterns help programming professionals address common problems in their programs. Here are some of the top benefits of using design patterns in your programs:

Types of design patterns

There are a few main types of design patterns you can use to write programs. Each type of design pattern has several subtypes. Here are the three common design pattern types:

Creational

Many programming languages, known as object-oriented programming languages, have elements called classes and objects. An object is a type of data you can create in a program that has a set of attributes. A class is a template you can use to create an instance of an object.

For example, you might create a program that uses a car as an object. Two attributes of the car are its color and type. You can include these attributes as data for the car object. Once youve defined the attributes of the car, you can use multiple classes to create different instances of the car object with different attributes, like a class with a red SUV and a class with a blue truck.

Creational design patterns are templates for creating classes and objects. Here are a few examples of creational design patterns:

Structural

A structural design pattern is a template for defining the structure and components of a class. These design patterns help programming professionals organize multiple classes and objects in their programs. Structural design patterns also assist with ensuring the efficiency and flexibility of a program.

Here are a few examples of structural design patterns:

Behavioral

A behavioral design pattern is a template that can help different classes in a program communicate with each other to accomplish the programs actions. In other words, these patterns define the way a programs objects behave.

Behavioral design patterns also help programmers write efficient algorithms or sequential steps in a program that perform a function. A real-world example of an algorithm is a math problem, which often requires a specific set of steps to complete. Programs operate in a similar fashion.

How to implement a design pattern

Here are steps you can take to use a design pattern to write a program:

1. Identify your needs

The first step to implementing a design pattern in a program is identifying what you need from your program. Not all programs need a design pattern to be effective. You may notice an issue with your program, like a lack of flexibility or efficiency, that a design pattern can solve.

For example, you may notice that a program youre writing includes multiple access points to a file, creating a security risk. You can use a design pattern to address this issue.

2. Choose a design pattern based on your needs

After you analyze what you need your program to accomplish, you can review design patterns. You can choose a pattern that fits your needs or solves the problem youre trying to address in your code.

From the example above, you can write your program so theres only one point of access to the object using a creational design pattern called the singleton.

3. Use the design pattern to write the program

Lastly, you can use the design pattern as a template to fulfill the purpose of the program. Heres an example of a Java program using the singleton design pattern:

public class Singleton {

private static Singleton instance = new Singleton();

private Singleton { }

public static Singleton getInstance() {

return instance;

}

}

The first line of the program begins the class with the name of Singleton. The second line creates an instance of the class. Note that this instance is a private variable, meaning users outside the Singleton class cant access its value or contents. The third line also uses the keyword private to protect the instance of the Singleton class from outside access. The fourth line features a method called getInstance(), which returns the value of instance (declared in the second line of the program) when called.

Please note that none of the companies mentioned in this article are affiliated with Indeed.

FAQ

What are the 3 types of patterns?

Design patterns are divided into three fundamental groups:
  • Behavioral,
  • Creational, and.
  • Structural.

What are different types of design pattern?

There are five well-known design patterns possible to implement in a wide scope of programming languages:
  • Abstract Factory Pattern.
  • Builder Pattern.
  • Factory Method Pattern.
  • Prototype Pattern.
  • Singleton Pattern.

What are the 4 basic categories for design patterns?

Although there are 23 design patterns listed in Design Patterns: Elements of Reusable Object-Oriented Software, of those there are 7 that are considered the most influential or important.

Related Posts

Leave a Reply

Your email address will not be published.