task.md

Task 1/2: What is code refactoring?

Refactoring is a process of modifying source code without changing its behavior. For example, this could involve renaming a method or extracting a magic constant into a separate variable. It improves code readability but doesn’t change what the code does.

The purpose of refactoring is to improve code readability and simplify its maintenance. Since software developers often work in teams on codebases and spend considerable time reading each other’s code, it is important to make your code clear and clean.

Let's take a look at two code snippets below.

Before refactoring:

public class Main {
    
    public static void main(String[] args) {
        double n = 5.0;
        double result = calculate(n);
        System.out.println("Circle area is: " + result);
    }

    public static double calculate(double r) {
        return 3.14159 * r * r;
    }
}

In this snippet of code, the method name calculate isn't descriptive, making it unclear what it calculates. The variable n and the method parameter r don't provide any information about their purpose. The constant 3.14159 is hard-coded within the method, leading to lack of clarity.

After refactoring:

public class Main {

    public static final double PI_VALUE = 3.14159;

    public static void main(String[] args) {
        double circleRadius = 5.0;
        double area = calculateCircleArea(circleRadius);
        System.out.println("Circle area is: " + area);
    }

    public static double calculateCircleArea(double radius) {
        return PI_VALUE * radius * radius;
    }
}

To improve the readability of the original snippet of code, the following refactorings were applied:

• The method calculate was renamed to calculateCircleArea to better express its purpose: calculating the area of a circle.
• The variable n was renamed to circleRadius for better code clarity.
• The parameter r was renamed to radius to improve code clarity.
• A PI_VALUE constant was extracted to hold the value of Pi, making the calculation formula more understandable and reusable.