//A2 extented to Monday Noon

int[] a;
int[] b;
a
b
a == b
a = new int[]{1,2,3};
int[] c = a;
c
int[] d={1,2,3};
int[] e={1,2,3};
e==f

//let's write equals method for two int arrays
//equal: if they are both null, or both have the same length and elemetns
int[] b;
int[] c = {65,42};
ArrayDemo.equals(b, c)
int[] d = {65, 42}
c==d
ArrayDemo.equals( c,d)
int[] a1 ={1,2,3}
int[] a2 = ArrayDemo.copyArray(a1, 3);
a1
a1 == a2
ArrayDemo.equals( a1, a2)

//swaping two elements in an array:
int [] a = {0, 1, 2, 3, 4, 5}
a[1]
a[4]
//let's swap a[1] and a[4]:
int tmp = a[1]
a[1] = a[4]
a[4] = tmp
ArrayDemo.displayArray(a, 0 , 5)

//let's write a swap method
ArrayDemo.swap(new int[]{1,2,3}, 0, 2)
int[] a3={1,2,3};
int[]  a4= ArrayDemo.swap(a3, 0, 2)
ArrayDemo.displayArray(a4, 0, 2))
ArrayDemo.displayArray(a3, 0, 2)) //what? a3 has changed as well!
a3
a4
a3 == a4  //a3 and a4 are the same object, why?
//look at swap, it does swap "in place" without creating a new array so it return the original pointer.
//Exercise: change swap such that it doesn't change the original array, and return the  result as a new array



Pizza p = new Pizza(3, "large");
p.addTopping("pineapple")
p.addTopping("pineapple")
p.addTopping("ham")
p.addTopping("extra cheese")

Pizza p2 = new Pizza(3, "small");
p.addTopping("extra cheese")
p.addTopping("ham")
p.addTopping("pineapple")
p.addTopping("pineapple")