Interface Exercise 1| Programming Using Java | Infosys Springboard

Introduction to Interface Exercise 1

Overview of the Problem Statement

• Shreyas introduces the video, focusing on solving an interface exercise related to tax calculations for an e-commerce company.

• The task involves implementing an application that calculates taxes based on customer purchases and seller locations, as per a provided class diagram.

Understanding the Tax Interface

• The problem includes a Tax interface with two implementing classes: PurchaseDetails and Seller.

• The calculateTax method is central to both classes, which will determine tax rates based on payment types and seller locations.

Implementation Steps in Eclipse IDE

Creating the PurchaseDetails Class

• In the PurchaseDetails class, three variables are declared: purchaseId, paymentType, and taxPercentage.

• A parameterized constructor initializes these variables. Getter and setter methods are also generated for encapsulation.

Tax Calculation Logic for Purchases

• The logic in the calculateTax method sets tax percentages based on payment type:

• Debit card: 2%

• Credit card: 3%

• Other payment methods: 4%

• The method returns the total amount after applying tax using the formula: price + (price * taxPercentage / 100).

Creating the Seller Class

• Similar to PurchaseDetails, the Seller class has two variables: location and taxPercentage.

• A parameterized constructor initializes these variables, followed by getter and setter methods.

Tax Calculation Logic for Sellers

Implementing Location-Based Tax Rates

• In the seller's calculateTax method, different tax percentages are assigned based on location:

• Canada: 22%

• Middle East: 15%

• Japan: 12%

• Europe: 25%

Finalizing Implementation

• Both classes return amounts after applying their respective taxes using similar formulas as in purchase calculations.

Testing the Implementation

Running Test Cases

• A tester class creates objects of both PurchaseDetails and Seller, invoking their respective calculate methods.

• [] (No specific timestamp provided here; general execution note.) Results are printed with two decimal precision to verify correctness before running test cases online.