Question

Write an application that reads an integer and determines and prints whether it’s odd or even. [Hint: Use the remainder operator. An even number is a multiple of 2. Any multiple of 2 leaves a remainder of 0 when divided by 2.]

Short answer

To determine if an integer is odd or even, use the remainder operator with 2 and check if the result is 0 (even) or not (odd).

Step-by-step solution

Understand the Remainder Operator

The Remainder Operator, also known as the modulo operator (% in most programming languages) finds the remainder after division of one number by another. In this exercise, we will use it to check if the number is divisible by 2 without a remainder, which means it's even.

Read the Integer

Prompt the user for an integer. You can do this by using input functions specific to your programming language, such as 'input()' in Python or 'Scanner.nextInt()' in Java.

Apply the Remainder Operator

After reading the integer, apply the remainder operator using the read integer and 2 as the operands (inputInteger % 2) to determine whether the number is even or odd.

Determine Evenness

The result from Step 3 will be either 0 or not. If the result is 0, the number is even; otherwise, it is odd. Use a conditional statement like 'if' to check the result and print the appropriate message.

Display the Result

Finally, based on the conditional check in Step 4, display a message to the user indicating whether the number is even or odd.

Key concepts

Remainder Operator in Java

In Java programming, the remainder operator, denoted as '%', plays a significant role in various computation tasks, particularly in determining numerical properties like evenness or oddness. This operator yields the remainder from the division of two integers.

For example, when you divide 5 by 2 using the remainder operator (5 % 2), the result would be 1, because 5 divided by 2 equals 2 with a remainder of 1. Similarly, if you evaluate 4 % 2, the outcome is 0 since 4 is evenly divisible by 2. It’s essential to understand that the remainder operator deals strictly with integers and does not provide a decimal result as typical division might.

Application in Determining Even and Odd Numbers

Specific to the exercise, using the remainder operator helps us determine if a number is even or odd. An even number will always give a remainder of 0 when divided by 2, which aligns with the concept that even numbers are multiples of 2. On the other hand, an odd number will result in a remainder of 1 when using the remainder operator with 2.

Even and Odd Number Determination

Knowing how to determine whether a number is even or odd is a fundamental concept in computer science and programming. In practice, you simply need to analyze if a number is divisible by 2 without a remainder to ascertain its evenness.

Identifying Evenness

To identify an even number within a program, apply the remainder operator with 2 as the divisor. If the expression looks like this number % 2, and it evaluates to 0, then 'number' is even. So using this logic, any integer that results in a value of 0 from this operation is classified as even. For instance, 8 % 2 equals 0; thus, 8 is even.

Distinguishing Oddness

On the flip side, an odd number will not be divisible by 2 evenly and will produce a remainder when using the remainder operator. If our expression number % 2 results in 1, the number is odd. For example, 7 % 2 equals 1; therefore, 7 is identified as an odd number.

Conditional Statements in Java

Conditional statements act as the decision makers of your program. In Java, one of the most commonly used conditional statements is the 'if' statement. It allows the program to decide between different courses of action based on whether a condition is true or false.

An 'if' statement looks something like this:
if (condition) { // Code to execute if 'condition' is true}
An accompanying 'else' can be used to provide an alternate action if the 'condition' is not true:
if (condition) { // Code to execute if 'condition' is true} else { // Code to execute if 'condition' is false}

In relation to our exercise involving even and odd number determination, the 'if' statement checks the result of using the remainder operator. If the result is 0, one block of code executes, printing that the number is even. If not, a different block of code prints that the number is odd.

This technique allows us to display a clear message to the user, guiding them towards understanding the numerical property of the integer input.