Code Refactoring

Checkpoint 1.49.1.

You will see a copy of the following code block in an interactive mode than you can modify and compile. We want you to improve the style of the code as an expert would view it. You must not change the code behavior. To ensure this you can run your refactored code and ensure that it passes all the test cases.

🔗

public class FinalPrice {
	public static double calculateFinalPrice(double basePrice, boolean isMember) {
		double discount = 0;
		if (isMember) {
			discount = basePrice * 0.1;
			System.out.println("Thank you for being a loyal customer!");
			System.out.println("Final price is: $" + (basePrice - discount));
		} else {
			discount = basePrice * 0.05;
			System.out.println("Join our membership for more discounts!");
			System.out.println("Final price is: $" + (basePrice - discount));
		}
		return basePrice - discount;
	}
}

public class FinalPrice {
	public static double calculateFinalPrice(double basePrice, boolean isMember) {
		double discount = 0;
		if (isMember) {
			discount = basePrice * 0.1;
			System.out.println("Thank you for being a loyal customer!");
			System.out.println("Final price is: $" + (basePrice - discount));
		} else {
			discount = basePrice * 0.05;
			System.out.println("Join our membership for more discounts!");
			System.out.println("Final price is: $" + (basePrice - discount));
		}
		return basePrice - discount;
	}
}
====
      import static org.junit.Assert.*;
import org.junit.Test;
import java.io.*;
import org.junit.Before;
import org.junit.After;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

public class RunestoneTests extends CodeTestHelper {

public RunestoneTests() {
	super("FinalPrice");
  }

// Test for member
  @Test
  public void testMember() throws IOException {
	Object[] args = {100.0, true};  // Arguments for the method (basePrice, isMember)
	
	// Capture the printed output
	ByteArrayOutputStream outContent = new ByteArrayOutputStream();
	System.setOut(new PrintStream(outContent));

// Run the method and get its return value
	String output = getMethodOutput("calculateFinalPrice", args);
	String expectedOutput = Double.toString(90.0);  // Expected price after 10% discount
	String expectedMessage = "Thank you for being a loyal customer!\nFinal price is: $90.0\n";
	
	// Check both output and printed message separately
	boolean outputMatches = getResults(expectedOutput, output, "calculateFinalPrice(100.0, true)");
	String actualMessage = outContent.toString();  // Get the printed message
	boolean messageMatches = expectedMessage.equals(actualMessage.trim());

assertTrue(outputMatches && messageMatches);  // Combine conditions here
  }

// Test for non-member
  @Test
  public void testNonMember() throws IOException {
	Object[] args = {100.0, false};  // Arguments for the method (basePrice, isMember)
	
	// Capture the printed output
	ByteArrayOutputStream outContent = new ByteArrayOutputStream();
	System.setOut(new PrintStream(outContent));

// Run the method and get its return value
	String output = getMethodOutput("calculateFinalPrice", args);
	String expectedOutput = Double.toString(95.0);  // Expected price after 5% discount
	String expectedMessage = "Join our membership for more discounts!\nFinal price is: $95.0\n";
	
	// Check both output and printed message separately
	boolean outputMatches = getResults(expectedOutput, output, "calculateFinalPrice(100.0, false)");
	String actualMessage = outContent.toString();  // Get the printed message
	boolean messageMatches = expectedMessage.equals(actualMessage.trim());

assertTrue(outputMatches && messageMatches);  // Combine conditions here
  }
}

🔗

Activity 1.49.1.

Which of the following code blocks is the most similar to your final refactored code for the previous question?

🔗

public class FinalPrice {
    public static double calculateFinalPrice(double basePrice, boolean isMember) {
        double discountRate = 0;
        String message = "";
        
        if (isMember) {
            discountRate = 0.1;
            message = "Thank you for being a loyal customer!";
        } else {
            discountRate = 0.05;
            message = "Join our membership for more discounts!";
        }

        double discount = basePrice * discountRate;
        System.out.println(message);
        System.out.println("Final price is: $" + (basePrice - discount));
        
        return basePrice - discount;
    }
}

You refactored correctly!

public class FinalPrice {
    public static double calculateFinalPrice(double basePrice, boolean isMember) {
        double discountRate = 0.05;
        String message = "Join our membership for more discounts!";
        
        if (isMember) {
            discountRate = 0.1;
            message = "Thank you for being a loyal customer!";
        }

        double discount = basePrice * discountRate;
        System.out.println(message);
        System.out.println("Final price is: $" + (basePrice - discount));
        
        return basePrice - discount;
    }
}

You refactored correctly!

public class FinalPrice {
    public static double calculateFinalPrice(double basePrice, boolean isMember) {
        double discountRate = 0;
        String message = "";
        
        if (isMember) {
            discountRate = 0.1;
            message = "Thank you for being a loyal customer!";
        } else {
            discountRate = 0.05;
            message = "Join our membership for more discounts!";
        }

        double finalPrice = basePrice * (1 - discountRate);
        System.out.println(message);
        System.out.println("Final price is: $" + finalPrice);
        
        return finalPrice;
    }
}

You refactored correctly!

🔗

Practice Code Structure

Section 1.49 Code Refactoring

Checkpoint 1.49.1.

Activity 1.49.1.