1Z0-811 Study Guide — How to Pass Oracle Java Foundations

Weeks 1–2

Java Basics: JDK vs JRE, compilation, main method, output, comments, variables, data types

Tip: Know the difference between compiling (javac Hello.java creates Hello.class bytecode) and running (java Hello executes the bytecode on the JVM). Know the eight Java primitive types: byte, short, int, long, float, double, char, boolean — their sizes and default values when declared as instance variables.

Weeks 3–4

Operators and Control Flow: arithmetic, comparison, logical operators, if/else, switch, loops

Tip: Know the difference between == (compares references for objects, values for primitives) and .equals() (compares content for objects). A common exam distractor is comparing two String objects with == — they may be different objects even if their content is identical, so == returns false while .equals() returns true.

Weeks 5–6

Object-Oriented Programming: classes, objects, methods, constructors, encapsulation, inheritance basics

Tip: Know the four pillars of OOP tested on 1Z0-811: Encapsulation (private fields, public getters/setters), Inheritance (extends keyword, subclass inherits superclass fields and methods), Polymorphism (same method name, different behaviour — method overriding), Abstraction (hiding implementation details). Know a simple example of each.

Weeks 7–8

Arrays, ArrayList, String methods, and basic exception handling

Tip: Arrays vs ArrayList: arrays have fixed size and can hold primitives; ArrayList is dynamic and requires objects (use Integer, not int). Know: array declaration (int[] arr = new int[5]), array access (arr[0]), ArrayList operations (add, get, set, remove, size). Know that ArrayList is in java.util and must be imported.