Practical Coding in Java
Learn to write and validate your own code
Darren Kessner, PhD
(revised May 2026)
Introduction
Why study computer science?
To the student
About the book
Resources
0. Hello, world!
Hello
Basics
Loops
Sequences
Coding Exercises: Hello
1. Functions and Testing
Conditions and Comparisons
Logical Operators
Functions
MonkeyTrouble
Coding Exercises: Functions and Testing
2. Strings and Math
Strings
HelloStrings
HelloMath
HelloRandom
Coding Exercises: Strings and Math
3. Loops and Algorithms
HelloLoops
HelloAlgorithms
Binimate
Coding Exercises: Loops and Algorithms
4. Classes and Objects
Person
PiggyBank
CoinFlipper
Circle
Coding Exercises: Classes and Objects
5. Arrays
HelloArrays
Average
Coding Exercises: Arrays
6. ArrayList
HelloArrayList
Coding Exercises: ArrayList
7. Array Algorithms
FindMin
Filter
Transform
Generate
Coding Exercises: Array Algorithms
Bonus Coding Exercises: Array Algorithms
8. Lists of objects
Animals
Coding Exercises: Lists of Objects
9. Inheritance and Interfaces
Person
Shape
Coding Exercises: Inheritance and Interfaces
10. 2D Arrays
Hello2DArrays
Coding Exercises: 2D Arrays
11. Composition
PetOwner
CrazyPetOwner
Coding Exercises: Composition
12. Algorithm Analysis
Coding Exercises: Algorithm Analysis
13. Recursion
Factorial
Coding Exercises: Recursion
14. File IO
HelloFile
LoadStrings
Coding Exercises: File IO
Appendix A: Numeric Conversion
Decimal and Hexadecimal
Converting from Decimal to Hex
Binary
Converting between Hex and Binary
Octal
Exercises: Numeric Conversion
Appendix B: Processing Libraries
Using the Processing libraries:
CLASSPATH
HelloProcessing
Bounce
Scenes
HighScores
Obstacles
Particles
RecursionDemo
TimeComplexity
Phyllotaxis
Coding Exercises: Processing Libraries
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Coding Exercises: File IO
Appendix A: Numeric Conversion
Next:
Decimal and Hexadecimal
