Computer Science 210
Data Structures

Fall 2017, Siena College

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ArrayFun BlueJ Project

Click here to download a BlueJ project for ArrayFun.

ArrayFun Source Code

The Java source code for ArrayFun is below. Click on a file name to download it.

ArrayFun.java

/**
 * A program to develop in class to review and experiment with
 * arrays.
 *
 * @author Jim Teresco and the Siena College CSIS 210 Fall 2017 Class
 */

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

public class ArrayFun
{
    public static void main(String args[]) {
        
        // declare an array with some ints
        // use a static initialization, which will allocate
        // space for the given number of ints and initialize them
        int static_a[] = { 23, 51, 1, 99, 49, 2, 10, 21, 17, 13 };
        
        // create our keyboard input Scanner
        Scanner keyboard = new Scanner(System.in);
        
        // prompt for and read values
        System.out.println("How many numbers? ");
        int count = keyboard.nextInt();
        
        System.out.println("Lower and upper bounds? ");
        int low = keyboard.nextInt();
        int high = keyboard.nextInt();
        
        keyboard.close();
        
        // declare and construct array
        int a[] = new int[count];
        
        // construct my Random object
        Random r = new Random();
        
        // loop to fill in array values
        for (int i = 0; i < a.length; i++) {
            a[i] = r.nextInt(high - low + 1) + low;
        }
        
        // print out our array, being sure to use the
        // array's length for our upper bound
        for (int i = 0; i < a.length; i++) {
            System.out.println("a[" + i + "] = " + a[i]);
        }
        
        // sequential search for largest and smallest
        int largest = a[0];
        int smallest = a[0];
        int largeIndex = 0;
        int smallIndex = 0;
        
        // search remaining items for smaller/larger values
        for (int i = 1; i < a.length; i++) {
         
            if (a[i] > largest) {
                largest = a[i];
                largeIndex = i;
            }
            
            if (a[i] < smallest) {
                smallest = a[i];
                smallIndex = i;
            }
        }
        
        System.out.println("smallest is : " + smallest + " at a[" + smallIndex + "]");
        System.out.println("largest is : " + largest + " at a[" + largeIndex + "]");
    }
}