Write a program with the following methods (in java) A method which takes one in

Question

Write a program with the following methods (in java)

A method which takes one integer parameter n which will be the size of an array. Using the parameter initialize an array of size n with random integer numbers between 1 and 20. This method should return the randomly generated array.

A method which takes one integer array parameter and displays the array.

A method which takes one integer array parameter and displays every element of the array at an even index.

A method which takes one integer array parameter and displays every odd element.

A method which takes one integer array parameter and prints the array in reverse order. You may not use a string to store the reverse, you can only print the array.

A method which takes one integer array parameter and prints only the first, middle, and last elements of the array. NOTE: An array with an even number of elements will have two middle elements, and an array with an odd number of elements will have only one middle element.

Write a main method which demonstrates the above methods. Ask the user for the size of the initial array.

Sample:

Explanation / Answer

ArrayNumbersTest.java

import java.util.Random;
import java.util.Scanner;

public class ArrayNumbersTest {

  
   public static void main(String[] args) {
       Scanner scan = new Scanner(System.in);
      
       System.out.print("Enter the number of elements: ");
       int n = scan.nextInt();
       int a[] = readArray(n);
       displayArray(a);
       evenIndexArrayDisplay(a);
       oddElementArrayDisplay(a);
       reverseArray(a);
       firstMiddleLastElements(a);
   }
   public static int[] readArray(int n){
       Random r = new Random();
       int a[] = new int[n];
       for(int i=0; i<n; i++){
           a[i] = r.nextInt(20)+1;
       }
       return a;
   }
   public static void displayArray(int a[]){
       System.out.print("Array: ");
       for(int i=0; i<a.length; i++){
           System.out.print(a[i]+" ");
       }
       System.out.println();
   }
   public static void evenIndexArrayDisplay(int a[]){
       System.out.print("Even Indexes: ");
       for(int i=0; i<a.length; i++){
           if(i % 2 == 0)
           System.out.print(a[i]+" ");
       }
       System.out.println();
   }
   public static void oddElementArrayDisplay(int a[]){
       System.out.print("Odd Elements:: ");
       for(int i=0; i<a.length; i++){
           if(a[i] % 2 != 0)
           System.out.print(a[i]+" ");
       }
       System.out.println();
   }
  
   public static void reverseArray(int a[]){
       System.out.print("Reverse: ");
       for(int i=a.length-1; i>=0; i--){
           System.out.print(a[i]+" ");
       }
       System.out.println();
   }
   public static void firstMiddleLastElements(int a[]){
       System.out.print("First, Middle, Last: ");
       System.out.print(a[0]+" ");
       if(a.length % 2 == 0){
           System.out.print(a[a.length/2]+" ");
           System.out.print(a[(a.length-1)/2]+" ");
       }
       else{
           System.out.print(a[a.length/2]+" ");
       }
       System.out.print(a[a.length-1]+" ");
   }
}

Output:

Enter the number of elements: 10
Array: 11 17 6 5 1 9 2 10 12 2
Even Indexes: 11 6 1 2 12
Odd Elements:: 11 17 5 1 9
Reverse: 2 12 10 2 9 1 5 6 17 11
First, Middle, Last: 11 9 1 2

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