Loose Coupling and Tight Coupling - Notes By ShariqSP

Loose Coupling and Tight Coupling in Java

In software engineering, coupling refers to the degree of dependency between modules or components within a system. Loose coupling implies that the components are relatively independent and can interact with each other with minimal dependencies. In contrast, tight coupling indicates strong dependencies between components, where changes in one component may have a significant impact on others. Let's explore loose coupling and tight coupling with examples:

1. Tight Coupling:

In a tightly coupled system, classes or modules are highly dependent on each other, making it challenging to modify or replace one component without affecting others. This often leads to code that is difficult to maintain and test.

Example of Tight Coupling:

In this example, the Order class is tightly coupled with the Payment class, as it directly creates an instance of Payment and calls its methods.

              class Payment {
                  public void processPayment(double amount) {
                      // Payment processing logic
                      System.out.println("Payment processed for amount: " + amount);
                  }
              }
              
              class Order {
                  private Payment payment;
              
                  public Order() {
                      this.payment = new Payment(); // Tight coupling
                  }
              
                  public void checkout(double amount) {
                      payment.processPayment(amount);
                  }
              }
              
              public class Main {
                  public static void main(String[] args) {
                      Order order = new Order();
                      order.checkout(100.0);
                  }
              }
                

2. Loose Coupling:

Loosely coupled systems have components that interact with each other through well-defined interfaces or abstractions, reducing dependencies and promoting flexibility. This makes the system easier to maintain, extend, and test.

Example of Loose Coupling:

In this example, the Order class is loosely coupled with the Payment interface. It depends on an abstraction (Payment) rather than a concrete implementation, allowing different payment methods to be easily plugged in without modifying the Order class.

              interface Payment {
                  void processPayment(double amount);
              }
              
              class CreditCardPayment implements Payment {
                  public void processPayment(double amount) {
                      // Credit card payment processing logic
                      System.out.println("Credit card payment processed for amount: " + amount);
                  }
              }
              
              class Order {
                  private Payment payment;
              
                  public Order(Payment payment) { // Loose coupling
                      this.payment = payment;
                  }
              
                  public void checkout(double amount) {
                      payment.processPayment(amount);
                  }
              }
              
              public class Main {
                  public static void main(String[] args) {
                      Payment payment = new CreditCardPayment(); // Create specific payment method instance
                      Order order = new Order(payment);
                      order.checkout(100.0);
                  }
              }
                

Loose coupling promotes modularity, maintainability, and scalability in software systems by reducing dependencies between components. It allows for easier code changes, testing, and integration of new features.

Advantages and Disadvantages of Tight Coupling

Advantages of Tight Coupling:

Disadvantages of Tight Coupling:

Understanding the advantages and disadvantages of tight coupling is crucial for making informed design decisions in software development.

Advantages and Disadvantages of Loose Coupling

Advantages of Loose Coupling:

Disadvantages of Loose Coupling:

Understanding the advantages and disadvantages of loose coupling is essential for designing resilient and scalable software systems.

Differences Between Loose Coupling and Tight Coupling

Interview Questions on Tight Coupling and Loose Coupling

Interview Questions:

1. What is tight coupling in software development?
2. Explain the concept of loose coupling.
3. Why is tight coupling considered a poor design practice?
4. How does tight coupling affect the maintainability of software systems?
5. What are the benefits of loose coupling in software architecture?
6. What design principles promote loose coupling?
7. How can dependency injection help in achieving loose coupling?
8. What is the difference between tight coupling and strong coupling?
9. Give an example of a tightly coupled system and suggest ways to refactor it for loose coupling.
10. How does loose coupling contribute to better scalability and flexibility in software systems?

Multiple Choice Questions (MCQs):

1. Which of the following statements best describes tight coupling?
   1. High dependency between modules
   2. Low cohesion between modules
   3. Strong independence between modules
   4. Loose connection between modules
2. Which design principle promotes loose coupling by allowing objects to depend on abstractions rather than concrete implementations?
   1. Encapsulation
   2. Inversion of Control (IoC)
   3. Single Responsibility Principle (SRP)
   4. Open/Closed Principle (OCP)
3. What is the primary goal of achieving loose coupling in software design?
   1. To improve code readability
   2. To minimize code duplication
   3. To increase system performance
   4. To enhance software maintainability
4. Which of the following scenarios is an example of tight coupling?
   1. Two modules communicate through a well-defined interface
   2. A class directly instantiates another class using the new keyword
   3. Modules interact through loosely coupled interfaces
   4. Dependency injection is used to manage object dependencies
5. Which design pattern promotes loose coupling by ensuring that classes depend on interfaces rather than concrete implementations?
   1. Singleton Pattern
   2. Observer Pattern
   3. Factory Pattern
   4. Strategy Pattern