// File:  ArrayIntro.java   

// Shows array processing basics: declaring an array, using "for" 
// statements to traverse it, and the "length" instance variable

import java.util.Random;

/**
 * A class to demonstrate the basics of array processing
 */
public class ArrayIntro
{
    public static void main(String[] args) 
    {
        Random r = new Random();

        int [] list = new int[10] ;   // an array that can hold up to 10 ints
        
        // ***** POPULATE the array *****
        
        // store 10 random ints between 0 and 99 in the array
        for (int i = 0 ; i <= 9 ; i++) 
        {
            int next = r.nextInt(100) ;
            list[i] = next ;
        }
        
        // ***** PROCESS the array *****
        
        // 1. print the array
        System.out.print("The array:  ");
        for (int i = 0; i < list.length ; i++) 
        {
            System.out.print( list[i] + "  " ) ;
        }
        System.out.println();

        // 2. compute the sum of the ints in the array
        int sum = 0;
        for (int i = 0; i < list.length ; i++) 
        {
            sum = sum + list[i] ;
        }
        System.out.println("\nThe sum of the ints in the array: " + sum);

        // 3. find the largest value in the array and its index
        int max = list[0] ;         // assume largest is in first element
        int indexOfMax = 0;         // first element has index 0

        // for all other elements...
        for (int i = 1 ; i < list.length ; i++) 
        {
            int current = list[i] ;	// get next int from list
            if (current > max)          // if greater than current max...
            {
                max = current;		// ...we have a new max
                indexOfMax = i;         // ... at this index (position)
            }
        }
        System.out.println("\nThe largest value in the array is " + max
                + " (at index " + indexOfMax + ")");
        
        // print the list backwards
        System.out.print("\nPrinting the array in reverse order:  ") ;
        for (int i = list.length - 1; i >= 0; i--) 
        {
            System.out.print( list[i] + "  " ) ;
        }
        System.out.println("\n") ;
    }
}

/*  sample output

The list:  69  61  69  42  85  52  73  38  40  89  

The sum of the ints on the list is 618

The largest value on the list is 89 (at index 9)

Printing the list in reverse order:  89  40  38  73  52  85  42  69  61  69 

*/