Learn Java Programming from Scratch with Examples and Demos

Compare low level and high level languages by showing how low level languages deal with hardware directly while high level languages enable easier, portable application development.

Compare procedural programming and object oriented programming, noting functions vs objects, top-down versus bottom-up approaches, data hiding and overloading with example languages.

Compare real-world objects and software objects, noting that both hold data and exhibit behavior. See software objects formed with data members and behavior, with cows and horses as examples.

Explore top-down vs bottom-up programming: top-down starts with a main task and breaks it into steps in procedural programming; bottom-up builds from models and integrates with objects in object-oriented programming.

Compare compiler and interpreter in programming: the compiler translates the whole program, the interpreter translates line by line, impacting error handling and speed.

Explore the basic features of Java as an object-oriented language, including compilation to bytecode, the role of the Java Virtual Machine, and the runtime environment that enables platform-independent, secure applications.

Explore how compilers and interpreters transform Java source code into bytecode, and how the resulting programs run consistently across different operating systems.

Explain why Java programs are machine independent, examine how the compiler enables portability, and discuss Sun Microsystems processor design that supports running across different processors.

Explore the differences between JDK, JRE, and JVM, showing how the JDK provides development tools and runtime, the JRE offers the execution environment, and the JVM interprets and runs code.

Identify Java reserved words and learn not to use them as identifiers like class or table names, otherwise the compiler reports an error.

Discover why BlueJ is ideal for beginners, featuring a simple, pedagogy-driven interface, interactive object work, and cross-platform portability for learning Java.

Learn how BlueJ highlights scope with color coding, enabling fast visual scanning, spotting misplaced brackets, and dynamically creating, inspecting, and manipulating objects during runtime.

Download BlueJ for free and use the portable Windows version that requires no installation. Run BlueJ from a folder on Windows 7 or later.

Master BlueJ by creating a new Java project, adding a class with a main method, writing simple statements, compiling, and running to display output on the screen.

Explore how binary operators drive arithmetic in Java, including plus, minus, multiply, and division, and see how integer and double types affect results.

Explore how operators work in Java, including prefix and postfix increment, binary operations, and precedence, with five practical examples and step-by-step explanations.

Explore Java operators through prefix and postfix increments, unary and binary operations, and operator precedence with practical examples.

Learn how to compute the diagonal of a square in Java using Math.sqrt, reading the side length with a Scanner and handling double input to print the result.

Learn to use the Math.pow method in Java to compute powers with user-provided values and display the result.

Write a Java program using Scanner to read two numbers, compare them with if-else, and print the square of the smaller number, handling equal inputs.

Learn to write a Java program that uses a Scanner to input triangle sides, checks the triangle inequality, and reports whether the triangle is equilateral, isosceles, scalene, or not possible.

Explore a Java program that uses if-else with character-based branching to process three numbers, compute their product for specific characters, and handle invalid characters.

Learn to use a for loop with a break statement to stop when the sum of two user-entered numbers becomes negative, while reading input via scanner and printing the result.

Learn how to use the continue statement in a for loop to skip negative user inputs and accumulate the sum of ten numbers, displaying results only for non-negative values.

Illustrates a Java program that prints natural numbers from 1, asking after each number if the user wants to continue, using Scanner input and an unfixed loop.

Learn to write a Java program that prompts for numbers, checks even or odd, and exits when zero, using a Scanner loop.

Explore the Java while loop to repeat a block of statements, print numbers 1 to 10, and contrast known versus unknown repetitions.

Explore reading natural numbers from 1 onward with while and for loops, showing how an infinite loop is created and broken. Compile, run, and observe the printed output.