Java

AP Computer Science A AP CSA Study Guide

A plain-language study guide to AP Computer Science A, one page per unit. Every idea the exam can ask about, explained for students, with links to practice.

AP Computer Science A AP CSA Practice Tests

Full-length AP Computer Science A multiple-choice practice tests. 42 questions, one at a time, with instant feedback and a breakdown of the ideas you missed.

AP Computer Science A AP CSA Practice Questions

Free AP Computer Science A multiple-choice practice, organized by unit and topic. Answer five random questions at a time and see the ideas behind each one.

Java Java Array Algorithms

A roadmap to the core array algorithms every Java student should know, from finding a minimum or maximum to searching for a value.

Java Java Math.random()

Are you working on Math.random() in your Java programming class? Here's an explanation and some practice problems to help you get better.

Java toString Method

Discover how Java's toString() method can help you debug more effectively and improve code readability with this comprehensive guide.

Java Order of Operations

We all learned PEMDAS in school, but the order of operations in Java is way more detailed.

InvocationTargetException Fix

An InvocationTargetException occurs in Java when you call a method through refection and that method throws an exception.