Question

Write a method isEven that uses the remainder operator (\%) to determine whether an integer is even. The method should take an integer argument and return true if the integer is even and \(\left.f_{\mathrm{a}}\right\rceil_{\mathrm{se}}\) otherwise. Incorporate this method into an application that inputs a sequence of integers (one at a time) and determines whether each is even or odd.

Short answer

Write an `isEven` method that returns `true` if `number % 2 == 0`, then use it in an application to check if user-input integers are even or odd.

Step-by-step solution

Understand the Problem

We need to write a method called `isEven` that determines whether a given integer is even by checking the remainder when divided by 2. It should return `true` if the integer is even and `false` otherwise.

Create the isEven Method

Define the `isEven` method that takes an integer `number` as its parameter. This method will return a boolean value based on the evaluation of `number % 2 == 0`.

Implement Remainder Operator Logic

In the `isEven` method, use the remainder operator `%` to determine if the number is even: `int remainder = number % 2`. If `remainder` equals 0, the number is even.

Return the Boolean Result

Return the result of the condition `number % 2 == 0` which will be `true` if the number is even and `false` if odd.

Setup the Application to Input Integers

Create a main application method to input a sequence of integers. Use a loop to continuously read integers from the user until a termination condition is met.

Use the isEven Method within the Application

For each integer input, call the `isEven` method to check if it is even or odd. Print "even" if `isEven` returns `true` and "odd" otherwise.

Key concepts

Method Implementation

In Java programming, implementing a method encapsulates a particular logic or functionality within a named block. This makes code easier to understand and reuse.
Developing the `isEven` method is an example of this concept. You start by defining a method signature with appropriate method access modifiers, return type, name, and parameters.
For instance, in our `isEven` method, the return type is `boolean` as it determines if a number is even (true) or odd (false). The method takes an integer parameter, which it's going to process. Here's a simple layout:

• Signature: `public static boolean isEven(int number)`
• Access modifier: `public` (to allow access from other classes)
• Static: To allow calling without creating an instance
• Return type: `boolean`
• Name: `isEven`
• Parameter: integer `number`

Utilizing method implementation effectively can lead to more structured and maintainable code, especially when you begin organizing similar logic into separate, easily callable methods.

Remainder Operator

The remainder operator `%` is a fundamental tool in programming, especially when working on arithmetic conditions like even or odd checks.
In Java, the remainder operator returns the remainder of a division, which can be helpful for various logical conditions beyond basic arithmetic.
For determining if a number is even, the logic `(number % 2 == 0)` is used. This checks if the remainder, when `number` is divided by 2, is zero. If true, the number is even.

Here’s a breakdown of its usage:

• `number % 2`: Computes the remainder of the division of `number` by 2
• `== 0`: Checks if the result of the above computation is zero
• If the remainder is zero, the number is even, hence the method `returns true`

By mastering the remainder operator, you can handle a variety of common computational tasks with greater ease and precision.

Boolean Logic

Boolean logic forms the backbone of decision making in programming. Java uses `boolean` data types to hold true or false values.
In the context of the `isEven` method, boolean logic determines the flow based on a condition. When you evaluate `number % 2 == 0`, you generate a `boolean` value (`true` or `false`).
This value is used to decide what action the program should take next.

Consider the steps:

• The method evaluates the expression `number % 2 == 0`
• The evaluation returns a boolean value: `true` if `number` is even and `false` otherwise
• The method returns this boolean value directly as its final output

Boolean logic helps create pathways for program execution, allowing Java applications to perform specific actions based on conditions, thus increasing their intelligence and functionality.

User Input Handling

Handling user input is a critical part of interactive Java applications. It allows programs to receive data from users and process it accordingly.
Java provides several ways to handle user input, but one common method is using the `Scanner` class. This class can capture different types of input from the user, helping in developing dynamic and responsive applications.

Here's how you might handle user input in the context of this exercise:

• Import the `Scanner` class: `import java.util.Scanner;`
• Create an instance of `Scanner`: `Scanner input = new Scanner(System.in);`
• Use a loop to continuously read integers: `while(condition) { int number = input.nextInt(); }`
• Process the number using `isEven` method and output results
• Decide a termination condition to break the loop (like a specific integer input indicating to stop)

Properly handling user input ensures a smooth interaction between the application and its users, making programs more intuitive and user-friendly.