/**
 * The code below highlights issues when passing object references
 * as inputs to methods: The methods can make permanent changes to
 * the objects at the end of the references! This can't happen when
 * passing primitive types.
 */
public class PassingParameters
{
    /**
     * This method changes its input value, and proves that 
     * it's been changed by printing out the new value.
     * @param n  The input value
     */
    public void addOne(int n) 
    {
        n = n + 1;
        System.out.println("After adding 1, n is "+n);
    }

    /**
     * This method calls addOne, above, but prints before and
     * after the call so we can see any changes addOne makes.
     */
    public void test()
    {
        int x = 100;
        System.out.println("Before: "+x);
        addOne(x);
        System.out.println("After: "+x);
    }

    /**
     * Method that takes an array of ints as its input, and increments
     * each of them. It does NOT have a return value...
     */
    public void incrementAll(int[] nums) 
    {
        for(int i=0; i<nums.length; i++) {
            nums[i] = nums[i]+1;
            System.out.println("Just updated to "+nums[i]);
        }
        System.out.println("Double-checking that they got incremented:");
        // You can use a for-each loop on an array!
        for(int m : nums) {
            System.out.println(m);
        }
    }

    public void testArray()
    {
        // Use initializer to provide initial values for array
        int[] data = {10,15,20};  
        // Pass the array to incrementAll method
        incrementAll(data);
        // Print out our array again to look for changes
        System.out.println("Back in testArray():");
        for(int n : data) {
            System.out.println(n);
        }
    }
    
}