All notes, in reading order

Java is a statically typed, object oriented language that compiles to bytecode and runs on a virtual machine, which is what makes it portable.

Java

Install a JDK, understand every word in the classic first program, and learn what compilation and execution actually do.

Java

Java has eight primitive types and everything else is a reference. Knowing which is which explains assignment, defaults and equality.

Java

Widening happens by itself, narrowing needs a cast and can lose data, and casting a reference only changes how the compiler sees an object.

Java

Java operators grouped by purpose, with the precedence rules, short circuit behaviour and integer arithmetic surprises that trip people up.

Java

Reading from the keyboard and writing to the console, with the Scanner pitfall that catches almost every beginner.

Java

The three comment forms, the reserved words you cannot use as names, and the naming conventions every Java codebase follows.

Java

Decision making in Java, from the plain if statement to modern switch expressions and pattern matching.

Java

Every looping construct in Java, when each one fits, and how break, continue and labels change the flow.

Java

A method groups a piece of behaviour behind a name, a parameter list and a return type, and that signature is the contract callers depend on.

Java

Several methods may share a name if their parameter lists differ, and the compiler decides which one runs before the program starts.

Java

A recursive method calls itself on a smaller problem, and it works only when a base case guarantees the shrinking stops.