JVM

Java operators: how operand types choose what a symbol does, identity versus equality, short-circuiting, precedence and increments.

Beginner to Intermediate9 cards · 5 qnot started

Choosing which code runs with if and switch, repeating it with Java's four loop forms, and the boundary mistakes in both.

Beginner to Intermediate9 cards · 5 qnot started

Java strings: immutability, why String methods return new strings, the string pool, equals against ==, and building text with StringBuilder.

Beginner to Intermediate9 cards · 5 qnot started

Java variables and types: primitives and references, what assignment copies, the eight primitive types, money, and what the compiler checks.

Beginner to Intermediate9 cards · 5 qnot started

Java methods: declaring and calling them, signatures, parameters and arguments, pass-by-value, and overloading.

Beginner to Intermediate10 cards · 6 qnot started

How a Java program runs: what javac produces, what the java command and the JVM do with it, and why one build runs on every machine.

Beginner to Intermediate6 cards · 5 qnot started

Java memory: the stack and the heap, what keeps an object alive for the garbage collector, the two memory errors, and leaks.

Intermediate to Advanced9 cards · 5 qnot started

Why shared state breaks between threads: race conditions, non-atomic operations, visibility, and choosing volatile, atomics or locks.

Intermediate to Advanced9 cards · 5 qnot started

Java polymorphism: how the runtime object chooses which overridden method runs, what the declared type decides, hiding, casts and instanceof.

Intermediate to Advanced9 cards · 5 qnot started

Java generics: type parameters, what the compiler checks, type erasure, wildcards, and what erasure forbids.

Intermediate to Advanced9 cards · 5 qnot started

Java threads: starting work that runs alongside your code, the states a thread passes through, and platform vs virtual threads.

Intermediate to Advanced8 cards · 5 qnot started

Locks in Java: what synchronized guarantees, which object it locks, reentrancy, ReentrantLock, and what a lock cannot protect.

Intermediate to Advanced9 cards · 5 qnot started