Java Program to Calculate Simple Interest

Program Structure and Explanation

The Java program to calculate simple interest consists of several key components:

• Class Definition: The class SimpleInterestCalculator encapsulates the entire program.
• Main Method: The main method is the entry point of the program where the logic is executed.
• Input Handling: Using the Scanner class to read inputs for principal amount, rate of interest, and time.
• Calculation: A method calculateSimpleInterest is defined to compute the simple interest.
• Output: The calculated simple interest is printed to the console.

Java Program

import java.util.Scanner;

/**
 * A class to calculate Simple Interest based on user inputs for principal, rate, and time.
 */
public class SimpleInterestCalculator {

    /**
     * Main method - entry point of the program.
     *
     * @param args Command line arguments
     */
    public static void main(String[] args) {
        // Create a Scanner object to read input
        Scanner scanner = new Scanner(System.in);

        // Prompt the user for principal amount
        System.out.print("Enter the principal amount: ");
        double principal = scanner.nextDouble();

        // Prompt the user for rate of interest
        System.out.print("Enter the rate of interest: ");
        double rate = scanner.nextDouble();

        // Prompt the user for time in years
        System.out.print("Enter the time in years: ");
        double time = scanner.nextDouble();

        // Calculate the simple interest
        double simpleInterest = calculateSimpleInterest(principal, rate, time);

        // Display the simple interest
        System.out.println("The Simple Interest is: " + simpleInterest);

        // Close the scanner
        scanner.close();
    }

    /**
     * Method to calculate simple interest.
     *
     * @param principal The principal amount
     * @param rate The rate of interest
     * @param time The time period in years
     * @return The calculated simple interest
     */
    public static double calculateSimpleInterest(double principal, double rate, double time) {
        return (principal * rate * time) / 100;
    }
}

Explanation

The program begins by importing the Scanner class to handle user input. The main method serves as the entry point of the application. It prompts the user to input the principal amount, rate of interest, and time period in years.

After collecting the inputs, the program calls the calculateSimpleInterest method, which computes the simple interest using the formula:

Simple Interest = (Principal * Rate * Time) / 100

Finally, the calculated simple interest is displayed to the user, and the Scanner object is closed to free up resources.