Java menu driven program to check positive negative or odd even number

A number is said to be a positive number if it is greater than 0 and if it is less than 0 then it is called a negative number. The negative number is followed by a minus sign (-) to identify it as a negative number.

A number is said to be an even number if it is divisible by 2 else it is called an odd number. In this article, we will see how to check if a number is positive, negative, or even, odd by using Java programming language. We will be implementing the application using a switch case. 

Problem Statement

Write a Java program to check positive negative or odd-even numbers ?

Input 1

Suppose the input number is 12.

Output 1

Checking it as a positive or negative number, it will result 12 as a positive number as it is greater than 0.

Input 2

Suppose the input number is -12.

Output 2

Checking it as a positive or negative number, it will result -12 as a negative number as it is less than 0.

Input 3

Suppose the input number is 2022.

Output 3

Checking it as an even or odd number, it will result 2022 as an even number as it is divisible by 2.

Input 4

Suppose the input number is 7.

Output 4

Checking it as an even or odd number, it will result 7 as an odd number as it is not divisible by 2.

Syntax

To perform operations like checking if a number is positive or negative, or it is even or odd we use an if else statement with some basic logic for each part mentioned above.

Following is the syntax for "if else statement"?

if(condition) {
   //code to be executed
}

Steps to check positive negative or odd-even number

Following are the steps to positive negative or odd-even numbers ?

• Ask the user to input the desired number.
• Display the menu.
• Ask the user to enter their choice.
• Use a switch case to go to the choice and perform the operation.
• Print the result.

Java menu driven program to check positive negative or odd even number

Let?s see the Java program to understand it clearly ?

<div class="code-mirror  language-java" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">import</span> <span class="token namespace">java<span class="token punctuation">.</span>util<span class="token punctuation">.</span></span><span class="token operator">*</span><span class="token punctuation">;</span>
<span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Main</span><span class="token punctuation">{</span>
   <span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token class-name">String</span> args<span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token keyword">int</span> num<span class="token punctuation">;</span>
      <span class="token class-name">Scanner</span> inn <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Scanner</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>in<span class="token punctuation">)</span><span class="token punctuation">;</span>
      mainLoop<span class="token operator">:</span> <span class="token keyword">while</span> <span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
         <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"\n***Menu***"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"1. Check if a Number is Positive or Negative"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"2. Check Whether a Number is Even or Odd"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"3. Terminate the program"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Enter action number (1-3): "</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token keyword">int</span> command<span class="token punctuation">;</span>
         <span class="token keyword">if</span> <span class="token punctuation">(</span>inn<span class="token punctuation">.</span><span class="token function">hasNextInt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
            command <span class="token operator">=</span> inn<span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"\nILLEGAL RESPONSE. YOU MUST ENTER A NUMBER."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            inn<span class="token punctuation">.</span><span class="token function">nextLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">continue</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span>

         <span class="token keyword">switch</span><span class="token punctuation">(</span>command<span class="token punctuation">)</span> <span class="token punctuation">{</span>
            <span class="token keyword">case</span> <span class="token number">1</span><span class="token operator">:</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">"Enter a number: "</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            num <span class="token operator">=</span> inn<span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">if</span><span class="token punctuation">(</span>num<span class="token operator">></span><span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
               <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Entered number "</span><span class="token operator">+</span>num<span class="token operator">+</span><span class="token string">" is positive."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
            <span class="token comment">//checks the number is less than 0 or not</span>
            <span class="token keyword">else</span> <span class="token keyword">if</span><span class="token punctuation">(</span>num<span class="token operator"><</span><span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
               <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Entered number "</span><span class="token operator">+</span>num<span class="token operator">+</span><span class="token string">" is negative."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
            <span class="token keyword">else</span> <span class="token punctuation">{</span>
               <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"The number is zero."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
            <span class="token keyword">break</span><span class="token punctuation">;</span>
            <span class="token keyword">case</span> <span class="token number">2</span><span class="token operator">:</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">"Enter a number: "</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            num <span class="token operator">=</span> inn<span class="token punctuation">.</span><span class="token function">nextInt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">if</span><span class="token punctuation">(</span>num <span class="token operator">%</span> <span class="token number">2</span> <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
               <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Entered number "</span><span class="token operator">+</span>num<span class="token operator">+</span><span class="token string">" is even."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
            <span class="token keyword">else</span> <span class="token punctuation">{</span>
               <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Entered number "</span><span class="token operator">+</span>num<span class="token operator">+</span><span class="token string">" is odd."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
            <span class="token keyword">break</span><span class="token punctuation">;</span>
            <span class="token keyword">case</span> <span class="token number">3</span><span class="token operator">:</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Program terminated"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">break</span> mainLoop<span class="token punctuation">;</span>
            <span class="token keyword">default</span><span class="token operator">:</span>
            <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"Wrong choice!!"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span>
      <span class="token punctuation">}</span>
   <span class="token punctuation">}</span>
<span class="token punctuation">}</span>
</div>

Output

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
1
Enter a number: 45
Entered number 45 is positive.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
2
Enter a number: 45
Entered number 45 is odd.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
1
Enter a number: -456
Entered number -456 is negative.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
2
Enter a number: 2022
Entered number 2022 is even.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
x
ILLEGAL RESPONSE. YOU MUST ENTER A NUMBER.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
ILLEGAL RESPONSE. YOU MUST ENTER A NUMBER.

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
5
Wrong choice!!

***Menu***
1. Check if a Number is Positive or Negative
2. Check Whether a Number is Even or Odd
3. Terminate the program
Enter action number (1-3):
3
Program terminated

In this article, we explored how to check if a number is positive, negative, or even, odd in Java by using a menu-driven approach.