// APS101, Winter 2009: Lecture 26 (Mar. 16)
//
// Review: last time we started writing the Pizza class
           as an example of how we can use 1-D arrays.

Pizza p = new Pizza(3, "medium");
p.toString()
p // automatically displays the output of the toString() method!
p.addTopping("pineapple")
p
p.addTopping("sardines")
p
p.addTopping("blue cheese")
p
p.addTopping("pepperoni") // doesn't add this one! why?
p

Pizza p = new Pizza(3, "medium");
p.addTopping("pepperoni")
p
p.addTopping("pepperoni")
p
p.addTopping("pepperoni") // unfortunately, can have duplicates.
p

// let's write one more method: removeTopping
// how would we go about doing this?
// 
// we could make the topping null, then fill the gap
// with the last element, and make the last element null.
// (or we could shift back the rest of the toppings to fill
//  the gap, but the order of the toppings doesn't matter, 
    so why make it slow?)

// For example, if we have:
// p = ["pineapple", "pepperoni", "anchovies"]

// We want to remove "pineapple".
// p = [null, pepperoni, anchovies]

// Then, we want to fill the null gap with anchovies.
// p = [anchovies, pepperoni, anchovies]

// Finally, we want to make the last element null.
// p = [anchovies, pepperoni, null]

(take a look at the removeTopping(String t) method in Pizza.java)

Pizza p = new Pizza(3, "small")
p
p.removeTopping("pepperoni") // nothing happens!
p.addTopping("pepperoni")
p
p.removeTopping("pineapple") // nothing happens again!
p
p.addTopping("anchovies")
p.addTopping("pineapple")
p
p.removeTopping("pineapple") // remove last-added topping
p
p.addTopping("pineapple")
p
p.removeTopping("pepperoni") // remove first topping
p

// 2-Dimensional Arrays
int[] a = new int[3]
int[][] b;
b
b = new int[2][3];
b
b[1][2] = 123;
b
b.length
b[0].length
b[1].length
b[2].length // error!
// b is a 2-D (2-dimensional) array
// b has 2 rows, 3 columns: 6 elements
// A 2-D array is an "array of arrays"

int[][] c = [3][];
int[][] c = new int[3][];
c
c[0] = new int[5];
c
c[1] = new int[3]; // can have different column lengths!
c
c[0].length
c[1].length