Intro to Java
About this free Intro to Java course
Intro to Java is a free introductory Java programming course for middle and high school students. Java powers Android apps, enterprise software, and Minecraft, and it's the language used in AP Computer Science A. That makes it a great choice for students who want a strong foundation in object-oriented programming.
You'll learn to write, think, and problem-solve like a software developer, covering variables, loops, conditionals, methods, and object-oriented programming. Each weekly lesson includes worked examples and a hands-on project, and you'll build everything from a letter generator and simple calculators to mini-games. Short companion videos on the STEM for Others YouTube channel walk through key topics like data types, string methods, arrays, and constructors.
Who this course is for
Intro to Java is designed for students in grades 8 through 12 with no prior programming experience. It's also a strong preparation course for students planning to take AP Computer Science A. You'll need a computer and a free Java editor such as Replit, BlueJ, or IntelliJ Community Edition.
Course outline
- Week 1: What is Java? How Java programs are compiled and run, and writing your first class with a main method.
- Week 2: Primitive data types and variables. int, double, boolean, and char, plus the Writing a Letter project.
- Week 3: Conditionals and loops. if / else statements, while loops, and for loops, with a practice project.
- Week 4: String methods. length(), substring(), indexOf(), equals(), and other tools for working with text.
- Week 5: String and object referencing. How Java stores objects in memory and why == and .equals() behave differently.
- Week 6: Review and challenge. A review of weeks 1-5 and a challenge project that combines everything so far.
- Weeks 7-8: Arrays and ArrayLists. 1D arrays, traversing arrays, arrays of strings, ArrayList, and 2D arrays.
- Weeks 9-11: Objects, classes, constructors, and methods. Designing your own classes, writing constructors, and building methods.
- Week 12 and beyond: OOP design, inheritance, and semester project. Inheritance and class design, followed by an original final project.
What you'll learn
- Write, compile, and debug Java programs
- Use variables, conditionals, loops, and String methods to solve problems
- Store and process data with arrays, 2D arrays, and ArrayLists
- Design classes with constructors, fields, and methods
- Apply inheritance and object-oriented design in a final project
How long it takes
Expect about 18 hours in total: one to two hours per weekly lesson, including the practice projects, plus extra time for the semester project. It fits comfortably into a school semester, and the course is fully self-paced.
Frequently asked questions about Intro to Java
Is Intro to Java really free?
Yes. Intro to Java is completely free, with no fees, subscriptions, or account required. STEM for Others is a 501(c)(3) nonprofit, and every course in our curriculum library is free for students, families, and teachers.
Does this course help with AP Computer Science A?
Yes. The course covers many of the core AP CSA topics, including primitive types, String methods, conditionals, loops, arrays, ArrayLists, classes, and inheritance. It isn't an official AP course, but it's a strong head start.
What comes after Intro to Java?
When you're comfortable with classes and arrays, continue with Intermediate Java, which covers interfaces, recursion, Big O notation, sorting and searching algorithms, and data structures.
How do I start the course?
Click Begin Course at the top of this page to open the full slide deck, and use the companion video lessons on the STEM for Others YouTube channel when you want a walkthrough. Work through one unit at a time and try the practice questions before moving on.
Do I get a certificate?
The self-paced Intro to Java materials don't include an official certificate. If you're taking the course through a STEM for Others chapter program, ask your chapter leader about recognizing your completion.
Can teachers and clubs use this curriculum?
Yes. Teachers, homeschool families, libraries, and after-school clubs are welcome to use the Intro to Java materials with their students at no cost. STEM for Others volunteers also teach our curriculum in partner schools and libraries. You can find a chapter near you or start one at your school.
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