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Week 01: Introduction to Java

Interactive visuals, reference guides, and exercise companions for IntelliJ, Git, binary, Java syntax, data types, Scanner, conditionals, and methods

Workbook 1a - IntelliJ IDE

Maven Project Structure

Interactive folder tree: pom.xml, src/main/java, src/test/java

Workbook 1b - Git & GitHub (via IntelliJ)

What is Version Control?

Timeline of commits with roll-back/roll-forward

Distributed Version Control

Server + multiple computers, each with full history

Git Concepts via IntelliJ

File color indicators, commit panel, Share to GitHub, push & pull

Module 1 - Introduction to Programming

8-bit clickable switches with decimal conversion and auto-count

Bytes & Storage Scale

Bit to Terabyte with real-world size examples

Module 2 - Introducing Java

Java Compilation Flow

.java -> javac -> .class -> JVM -> machine code (step-by-step)

JDK / JRE / JVM Layers

Nested boxes showing what contains what

Module 3 - Basic Java Syntax

Data Types & Memory Sizes

All primitive types + String with proportional size bars

Final Constants (Read-Only Variables)

Declare once, never change — the final keyword, UPPER_SNAKE_CASE, magic numbers

Java Naming Conventions

camelCase, PascalCase, packages — interactive quiz with good/bad examples

Integer Division

Why 10 / 3 = 3 in Java — truncation visual and how to fix it

Pre/Post Increment & Decrement

Step-through: x++, ++x, y=x++, y=++x with variable tracking

Widening vs Narrowing

Cup analogy for safe vs unsafe type conversions

printf Format Specifiers

Interactive formatter: pick %d, %f, %.2f, %s and see output

Scanner Buffer (CRLF Problem)

Step-by-step buffer showing the nextInt/nextLine issue and fix

Module 4 - Conditionals & Methods

if/else Flowchart

Slider to change age, watch code highlight and flowchart update

Logical Operators: && || !

Interactive truth tables and real-world scenario builder

String Comparison: == vs .equals()

Why == fails for Strings and what to use instead

Method Signature Anatomy

Hover each keyword in "public static int add(int x, int y)" to learn what it means

Method Call Stack

Step-through: main() calls add(), stack frames push/pop

Method Decomposition

Watch a monolithic main() get refactored into small, focused methods step by step

Scanner in Multiple Methods

Compare 3 approaches: re-declare, static, pass as parameter (preferred)

switch Statement Flow

Old syntax (break) vs Java 14+ arrow syntax, click different values

Putting It All Together

From Problem to Code

4-step process: Read, Identify, Plan, Translate — walkthrough with the Sandwich Shop exercise

Quick Reference Guides

Week 1 Cheat Sheet

Quick reference for all Java fundamentals — keep this open while you code

Glossary / Key Terms

All Week 1 vocabulary — searchable, with examples

IntelliJ Shortcuts & Tips

Keyboard shortcuts, postfix templates, live templates, and pro tips — Windows & Mac

Common Errors Guide

Top mistakes from Week 1 exercises — what went wrong and how to fix it

Exercise companions help you understand each exercise — what to build, what a successful run looks like, and which concepts you need. No solutions, no spoilers.

Workbook 1a

Print a personal shopping list of 10+ items using System.out.println()

Workbook 1c - Operators

VariableApp + Receipt

Declare variables of different types, print them, and calculate a purchase total

Math Application

Solve 8 math problems using Java's Math class methods (max, min, pow, sqrt, abs, random)

Workbook 1c - Scanner & I/O

Basic Calculator

Read two numbers, show a menu of operations, and multiply them together

Payroll Calculator

Calculate gross pay with overtime — if/else logic and formatted output

Workbook 1c - Conditionals

Size selection + age-based discounts — if/else logic with formatted pricing

Sandwich Shop 2 (Loaded Option)

Add a "loaded" upgrade to the sandwich shop — more conditionals and mixed input

Workbook 1c - Methods

Method Practice

4 small programs practicing void methods, reusable methods, String returns, and boolean returns

Payroll Calculator 2 (Refactor)

Refactor payroll calculator into methods — same output, better structure

Rental Car Calculator

Calculate rental cost with optional extras and underage surcharge — conditionals, constants, and formatted output

Practice what you learned with interactive games — test your knowledge, race the clock, and have fun.

Data Types & Variables

Match values to their Java data type — timed and scored

Will this assignment compile, need a cast, or crash?

Name That Convention

camelCase, PascalCase, or UPPER_SNAKE_CASE? Know your naming rules

Code Reading & Output

Output Predictor

Read the code, predict the output — integer division, increment, concatenation

Pick the right printf format specifier to get the perfect output

Find the bug in the code and pick the fix — 15 common Week 1 errors

Control Flow

Condition Crafter

Trace if/else chains and logical operators — which branch runs?

Trace the switch — will it break or fall through?

Methods

Read the description, pick the correct method signature

Binary & Vocabulary

Binary Challenge

Convert between decimal and binary — race the clock

Test your Java vocabulary — 35 terms and definitions from Week 1

Git & IntelliJ

Complete Git tasks using IntelliJ — commit, push, pull in a mock IDE

Capstone

Junior developer simulator — survive your first day at ByteDrive Rentals fixing bugs and writing code