Assignment8.java

import java.util.Scanner;
public class Assignment8 {
   //Simple method for printing arrays.
   public static void printArray( int [] array ) {
      for( int i = 0; i < array.length; i++ ) {
         System.out.print( array[i] + " " );
      }
      System.out.println();
   }

   //Method that initalizes the array elements to their index + 1, so
   // 1 2 3 4 5 ....
   public static void initializeArray( int [] array ) {
      for( int i = 0; i < array.length; i++ ) {
         array[i] = i + 1;
      }
   }

   //TODO: Write a method that squares each element of the array and
   //and returns the result. Note: we did something very close with
   //a method that doubled each element of the array.
   public static int [] squareArray( int [] array ) {
      for(int i=0; i<array.length; i++) {
         array[i] = array[i] * array[i];
      }
      return array;
   }

   //TODO: Write a method that reverses all elements of the array and
   //and returns the result. NOTE: This is in the book! You may use the
   //book's code.
   public static int [] reverseArray( int [] array ) {
      int len = array.length;
      int[] newArray = new int[len];
      for (int i=0; i<len; i++) {
        newArray[(len-1)-i]=array[i];
      }
      return newArray;
   }

   //TODO: Write a method that transposes each pair of elements in the
   //array. It swaps each element with the element next to it, so
   // For even size: 1 2 3 4 5 6 transposed is 2 1 4 3 6 5, and
   // For od size:   1 2 3 4 5 transposed is 2 1 4 3 5
   public static int [] transposeArray( int [] array ) {
      for (int i=0; i<array.length-1; i+=2) {
         int temp = array[i];
         array[i] = array[i+1];
         array[i+1] = temp;
      }
      return array;
   }

   //The main method does not need to be changed. It is complete.
   //You only need to fill in the three methods directly above.
   public static void main ( String [] args ) {
      int arraySize = 0;
      Scanner input = new Scanner(System.in);

      //Creates an array of numbers. Size based on user input.
      System.out.print("Enter size of array: ");
      arraySize = input.nextInt();
      int [] numbers = new int [arraySize];

      //Initialize and print array using given methods.
      initializeArray( numbers );
      System.out.println("Values in array are:");
      printArray(numbers);

      //Square all the numbers in the array and print.
      numbers = squareArray(numbers);
      System.out.println("Values in array when squared are:");
      printArray(numbers);

      //Re-initialize then reverse all the numbers in the array and print.
      initializeArray( numbers );
      numbers = reverseArray(numbers);
      System.out.println("Values in array when reversed are:");
      printArray(numbers);

      //Re-initialize then transpose all the numbers in the array and print.
      initializeArray( numbers );
      numbers = transposeArray(numbers);
      System.out.println("Values in array when transposed are:");
      printArray(numbers);
   }
}