Introduction

• High-level OOP language
• Compiled + interpreted language
• Platform-independent language (Java run on JVM)
  • Same .class file can run on any OS.
  • Compiler compiles code and converts to platform-independent byte code.
  • Only condition to run byte code is the machine have a JRE.
• Has a Garbage Collector.

Java code (.java)
   ↓ compile
Bytecode (.class)
   ↓
JVM (Java Virtual Machine)
   ↓
Windows / macOS / Linux

JVM, JRE, JDK, JIT, JAR

String

Exception

Composition & Aggregation

Java Collection

Stream

Async

Comparator

Thread

Design Pattern