Book Image

Introduction to Programming

By : Nick Samoylov
Book Image

Introduction to Programming

By: Nick Samoylov

Overview of this book

Have you ever thought about making your computer do what you want it to do? Do you want to learn to program, but just don't know where to start? Instead of guiding you in the right direction, have other learning resources got you confused with over-explanations? Don't worry. Look no further. Introduction to Programming is here to help. Written by an industry expert who understands the challenges faced by those from a non-programming background, this book takes a gentle, hand-holding approach to introducing you to the world of programming. Beginning with an introduction to what programming is, you'll go on to learn about languages, their syntax, and development environments. With plenty of examples for you to code alongside reading, the book's practical approach will help you to grasp everything it has to offer. More importantly, you'll understand several aspects of application development. As a result, you'll have your very own application running by the end of the book. To help you comprehensively understand Java programming, there are exercises at the end of each chapter to keep things interesting and encourage you to add your own personal touch to the code and, ultimately, your application.
Table of Contents (21 chapters)

JVM architecture

JVM architecture can be described in terms of the runtime data structure in the memory and in terms of the two subsystems that use the runtime data – the classloader and execution engine.

Runtime data areas

Each of the runtime data areas of JVM memory belong to one of two categories:

  • Shared areas, which include the following:
    • Method area: Class metadata, static fields, methods bytecodes
    • Heap area: Objects (state)
  • Not shared areas, dedicated to each application thread, which include the following:
    • Java stack: Current and caller frames, each frame keeping the state of Java (not native) method invocation:
      • Values of local variables
      • Method parameters values
      • Values of operands for intermediate calculations...