Author: Lim Wei Liang

Semester Taken/Lecturer: AY20/21 Special Term 1 under Dr Boyd Anderson

Note: Content taught is equivalent to that of 2030S AY20/21 Semester 2

Main References:

CS2030 Programming Methodology II

The Java™ Tutorials

Units 00 - 03: Introduction

1. Why CS2030?

• Real-world code is complex, evolves continuously, and is the product of teamwork.
• Write 'better' code through programming paradigms, idioms, and language design. (e.g. Object-oriented Programming (OOP), and Functional Programming)
  • more human-friendly
  • easier to change and maintain
  • fewer crashes
• Programming Paradigms
  • imperative (how to deduce the solution, e.g. procedural, OOP)
  • vs declarative (assertion of truth e.g. logic, functional programming)
• Not a module about:
  • algorithms or efficiency, software engineering, Java language and libraries

2. Java Basics

• What is Java?
  • a verbose, compiled, cross-platform language
  • high-level (abstraction penalty?) and multi-threaded
  • statically typed, object-oriented and class-based inheritance general purpose programming language
• Compiled vs Interpreted Languages - compiler is our friend
  • Java Workflow: source code → compiler → compiled into java bytecode ahead of time→ just in time interpreted and run by the JVM
  • helps us to catch errors early, but can only detect errors based on the static code, not from running it (runtime errors)
  • prefer to catch errors in the compilation phase as compared to runtime phase
  • to run code more interactively, we can use jshell, which is a REPL (Read-Evaluate-Print-Loop) interpreter, runs off .java files
• Java Memory Management
  • Stack - for storing activation records of method calls, a method's local variables are stored here, is FILO
  • Heap - for storing Java objects upon invoking new, garbage collection done here

3. Taming Complexity