Question

Exercise 5: Design and implement a Java program (name it ArrayMethods), that defines 4 methods as follows:

int arrayMax(int[] arr) determines and returns the largest value within an array
int arrayMin(int[] arr) determines and returns the smallest value within an array
void arrayReverse(int[] arr) reverses the array (for example: 7 8 1 2 becomes 2 1 8 7) 
void arraySquared(int[] arr) changes every value within the array to value²

Test your methods by creating an array of length 5 within your main() method and filling it with random integers between 1 and 1000. Your program should then invoke the methods in the order listed above to display the original array, the largest number in the array, the smallest number in the array, the reversed array, and the square of each value in the array. Your main() method should invoke each method exactly once, with each invocation use the original array (modified by a previous invocation of a method, if the array was modified by a method) as the actual parameter. All methods must be designed to handle arrays with any number of elements. Use only one array in your program. All printing must be done by the main() method. Document your code and organize the output using appropriate formatting techniques.

Answer 1

Here is code:

import java.util.Random;
public
class HelloWorld {

public
static void main(String[] args)
{

int arrayLength = 5;
int[] array = new int[arrayLength];
Random rand = new Random();
// creating random numbers
for (int i = 0; i < arrayLength; i++) {
array[i] = rand.nextInt(1000);
}
// printing the numbers
System.out.print("Elements in array : ");
for (int i = 0; i < arrayLength; i++) {
System.out.print(array[i] + " ");
}
// max element in array
System.out.print("\nMaximum Elements in array : " + arrayMax(array));
// min element in array
System.out.print("\nMinimum Elements in array : " + arrayMin(array));
// reversing the elements
arrayReverse(array);
System.out.print("\nReversing Elements in array : ");
for (int i = 0; i < arrayLength; i++) {
System.out.print(array[i] + " ");
}
// squaring the element in array
arraySquared(array);
System.out.print("\nSquaring of Elements in array : ");
for (int i = 0; i < arrayLength; i++) {
System.out.print(array[i] + " ");
}
}
// get max element
public
static int arrayMax(int[] arr)
{
int max = arr[0];
// loops from 0 to arr length
for (int i = 0; i < arr.length; i++) {
if (arr[i] > max)
max = arr[i];
}
return max;
}
// get min element
public
static int arrayMin(int[] arr)
{
int min = arr[0];
for (int i = 0; i < arr.length; i++) {
if (arr[i] < min)
min = arr[i];
}
return min;
}
// get reverse element
public
static void arrayReverse(int[] arr)
{

int[] reversedArray = new int[arr.length];

for (int i = 0; i < arr.length / 2; i++) {
int tmp = arr[i];
arr[i] = arr[arr.length - 1 - i];
arr[arr.length - 1 - i] = tmp;
}
}
// get square element
public
static void arraySquared(int[] arr)
{
for (int i = 0; i < arr.length; i++) {
arr[i] = arr[i] * arr[i];
}
}
}

output:

Elements in array 437 459 121 357 164 Maximum Elements in array 459 Minimum Elements in array 121 Reversing Elements in array 164 357 121 459 437 Squaring of Elements in array 26896 127449 14641 210681 190969