// APS101, Winter 2009: Lecture 24 (Mar. 10)
//
// Before we begin, let's review some Input/Output from yesterday's Lab 6.
// (we wrote method FileAccess.displayFile)
//
// Also, let's briefly go over JavaDoc comments
// (you will need to write these for A3)
//
// Need to use 2 special tags:

- use @param to describe the parameters of a method
Syntax: @param p_name1 comment
        @param p_name2 comment
        ...

- use @return to specify the return type of a non-void method
Syntax: @return comment

* there should be only ONE @return tag for any non-void method (function) *

// Review: last time we started talking about arrays.
//
// what are some advantages of arrays?
// what are some disadvantages of arrays?
//
// we also wrote method ArrayDemo.displayArray
// similar to String's substring method
//
// ex. on ONE line, declare an integer array of size 3, with
// the following contents: {3, 2, 1}, and print out the 2nd and 3rd
// elements of this array.

ArrayDemo.displayArray(new int[] = {3, 2, 1}, 1, 2) // doesn't work!
ArrayDemo.displayArray(int[] = {3, 2, 1}, 1, 2) // also doesn't work!
ArrayDemo.displayArray(new int[]{3, 2, 1}, 1, 2)

// recall that you can declare and initialize an array in 3 ways:

// 1) int[] a = new int[3];
      a[0] = 3;
      a[1] = 2;
      a[2] = 1;

// 2) int[] a = new int[]{3, 2, 1};

// 3) int[] a = {3, 2, 1};

// what is the array equivalent of String's charAt method?
// trick question: elements in an array are always retrieved using an index
                   ex. a[0]

// what is the array equivalent of String's indexOf method?
// let's write our own: method findElement in ArrayDemo.java
// (notice the difference in efficiency between Versions 1 and 2)

ArrayDemo.findElement(new int[]{1, 2, 3}, 2)
ArrayDemo.findElement(new int[]{1, 2, 3}, 3)
ArrayDemo.findElement(new int[]{1, 2, 3}, 4) // returns -1!

// how do you test whether 2 arrays have the same contents?

int[] a = {1, 2, 3};
int[] b = {1, 2, 3};

a == b // remember that a and b are objects... in different memory locations!
// need to write our own method that tests equality of arrays

// how do you copy the contents of one array to another?

a = b // this doesn't copy contents of b into a! it copies reference of b to a!
a == b // a and b point to the same array now

a[0] = 10
a[0]
b[0]

// as you can see, arrays a and b are now the same!