💻 Java Programming from Scratch for Complete Beginners

The Lifecycle of a Java Program

19 min

Variables and Scopes: Where a Variable Lives and Dies

16 min

Data Types: Primitives vs Objects, and Why `int` and `Integer` Are Not Twins

12 min

Type Casting: Widening, Narrowing, and the Bugs Hiding in Between

16 min

Math Operations: Integer Division, Modulo, Overflow, and the LeetCode Traps They Cause

13 min

Conditionals and Loops: if/else, switch, for, while, and Nested Loops Without Tears

17 min

Arrays: Declaring, Indexing, Traversing, and the Famous IndexOutOfBounds

14 min

2D Arrays: Matrices, Rows, Columns, and Grid Traversal Patterns

14 min

2.3 Strings and Their Methods: charAt, substring, split, equals vs ==

19 min

String Immutability and StringBuilder: Why Loops + String Concat = Slow Code

15 min

Core Problem Patterns: Two Pointers and Frequency Counting

19 min

Practice Lab: Solving 5 Classic Easy Problems Using Only Arrays and Strings

13 min

Basics of OOP: Classes, Objects, Attributes, and Methods

14 min

Constructors, `this`, and the Object Lifecycle from `new` to Garbage Collection

18 min

Access Specifiers and Encapsulation: Private Fields, Getters, Setters, and Why

17 min

Inheritance and Method Overriding: Reusing Code Without Copy-Paste

17 min

Polymorphism, Abstraction, and Interfaces: One Reference, Many Behaviors

14 min

Method Overloading, static, final, and Pass by Value (Java Has No Pass by Reference, Really)

14 min

Nested Classes and Initializer Blocks: When a Class Lives Inside Another 🪆

19 min

Packages and Modules: Keeping Code Organized as It Grows 🗂️

14 min

Enums and Records: Cleaner Code with Less Boilerplate ⚡

17 min

Annotations and Static vs Dynamic Binding: What Runs When, and Why @Override Saves You 🔍

12 min

Exception Handling: try, catch, finally, Checked vs Unchecked 💥

12 min

Custom Exceptions and Writing Code That Fails Politely 🎨

15 min

Collections Overview and Generics: Type-Safe Containers Explained Simply

12 min

Array vs ArrayList, and Mastering List for Dynamic Data

15 min

Set: HashSet, TreeSet, and Instant Duplicate Detection

12 min

Map: HashMap, the Single Most Used Tool in LeetCode Solutions

17 min

Map: HashMap, the Single Most Used Tool in LeetCode Solutions

18 min

Iterator and Choosing the Right Collection: A Decision Guide with Big O Costs

19 min

How to Read a LeetCode Problem: Inputs, Outputs, Constraints, and Edge Cases

18 min

Big O in Plain English: Judging Your Solution Before Submitting

12 min

Guided Solves: Two Sum, Valid Parentheses, and Top K Frequent Elements

18 min

Project Build: A Console "Problem Tracker" App Using Classes, Enums, and Collections

18 min

Project Polish: Exception Handling, Packages, and Clean Structure

17 min

Handover and Next Steps: Your Path to Spring Boot and Harder Problems

16 min