Day 3

static

null reference

Java Arrays

Type[] arrayName = new Type[elements count];

int[] array1 = new int[10];

String[] array1 = new String[10];

Object[] array1 = new Object[10];

MyType[] array1 = new MyType[10];

String[] colors = new String[] {“red”, “blue”, “white”};

How To Access Elements?

String[] friends = new String[10];

friends[0] = “Oleg”;

friends[1] = “Alex”;

friends[3] = “Irina”;

System.out.println(friends[1]);

System.out.println(friends[3]);

Multidimensional arrays

Type[][] arrayName = new Type[rows count][columns count];

Java Loops

while (condition) { ….}

do { ….} while (condition);

for (counter; condition; increment) { ….}

Goals

Packages

(Private, Protected, Public, default)Access Levels

Private – this class only

Protected – this class and children

Public – no limits

default – package private

Encapsulation

final

Interfaces

Class casting

Never, Never, Never, Never Give Up!