Java Programming Course Notes

Course Introduction

• Instructor: Mosh Hamedani
• Course Objective: Learn Java programming from basics to advanced features.
• Experience: Mosh has 20 years of software engineering experience and has taught over 3 million people.
• Coding School: Code with Mosh

Tools Installation

Java Development Kit (JDK)

• JDK: Software development environment for building Java applications.
• Components: Compiler, libraries, Java Runtime Environment (JRE), etc.
• Download: Available for various platforms (Linux, Mac, Windows).
• Mac Installation: Download and install .dmg file from Oracle's website.

Code Editors

• Popular Editors: NetBeans, Eclipse, IntelliJ IDEA.
• Recommendation: IntelliJ IDEA (Community Edition is free and sufficient for the course).

Java Basics

Anatomy of a Java Program

• Smallest Building Blocks: Functions (e.g., sendEmail(), convertWeight()).
• Function Structure: Return type, function name, parameters, body.
• Main Function: Entry point for Java programs (public static void main(String[] args)).
• Classes: Containers for functions (methods); follow Pascal Naming Convention (e.g., Main).
• Access Modifiers: Public, private (e.g., public class Main).

Coding and Execution

• Project Creation: Use IntelliJ IDEA to create Java projects.
• First Program: "Hello World" A basic program to understand Java code structure and execution.
• Compilation: Converts Java code to bytecode using the JDK's compiler.
• Execution: Uses Java Virtual Machine (JVM) to run bytecode.

Interesting Facts About Java

• Developer: James Gosling in 1995 at Sun Microsystems.
• Name Origin: Named after Java coffee; former names were Oak and Green.
• Java Editions: Standard Edition (core), Enterprise Edition (large-scale systems), Micro Edition (mobile), Java Card (smart cards).
• Global Use: 9 million developers; runs on 3 billion mobile phones, 120 million TV sets.
• Job Market: Average Java developer salary is $100,000/year in the US.

Course Structure

• Parts: 4 parts, each 3-4 hours long.
• First Part: Fundamentals of Java programming (variables, data types, control flow, etc.).
• Projects: Mortgage calculator to practice learned concepts.
• Advanced Parts: Object-Oriented Programming, Core Java APIs, Advanced Java features like streams, threads, database programming.

Fundamentals of Programming in Java

Variables and Constants

• Declaration: int age = 30; (must initialize before use).
• Types: Different data types (byte, short, int, long, float, double, char, boolean).
• Non-Primitive Types: Reference types (e.g., Date, Point); use new keyword.
• Constants: Use final keyword (e.g., final float PI = 3.14F;).

Type Conversion

• Implicit Casting: Automatic when no data loss (e.g., byte to int).
• Explicit Casting: Manual when potential data loss (e.g., double to int).
• String Conversion: Convert strings to numerical values using wrapper classes (e.g., Integer.parseInt()).

Operators

• Arithmetic Operators: +, -, *, /, %.
• Augmented Assignment Operators: +=, -=, *=, /=, %=.
• Pre/Post Fix Operators: Increment (++) and decrement (--) operators.
• Order of Operations: Parentheses, multiplication/division, addition/subtraction (PEMDAS).

The Math Class

• Methods: Math.round(), Math.ceil(), Math.floor(), Math.max(), Math.min(), Math.random().
• Formatting Numbers: Use NumberFormat class for currency and percent formatting.

Strings

• Declaration: String message = "Hello World";.
• Common Methods: length(), indexOf(), replace(), toLowerCase(), toUpperCase(), trim(), startsWith(), endsWith().
• Escape Sequences: \n, \t, \", \\.

Reading Input

• Scanner Class: Scanner scanner = new Scanner(System.in);.
• Methods: nextInt(), nextFloat(), nextDouble(), nextLine().

Arrays

• Single-Dimension Array: int[] numbers = {1, 2, 3, 4, 5};.
• Multi-Dimensional Array: int[][] matrix = {{1, 2, 3}, {4, 5, 6}};.
• Array Methods: Use Arrays class (e.g., Arrays.toString(array), Arrays.sort(array)).

Control Flow

Comparison and Logical Operators

• Comparison: ==, !=, >, >=, <, <=.
• Logical: && (and), || (or), ! (not).

Conditional Statements

• If-Else Statements: if, else if, else.
• Switch Statements: switch(variable) { case value: // code; break; default: // code; }.
• Ternary Operator: condition ? trueExpression : falseExpression.

Loops

• For Loop: for (initialization; condition; update) {}.
• While Loop: while (condition) {}.
• Do-While Loop: do {} while (condition); (executes at least once).
• For-Each Loop: for (dataType item : collection) {}.
• Break and Continue Statements: break; (terminates loop), continue; (skips to next iteration).

Project: Mortgage Calculator

• Loan Calculation: Principal, annual interest rate, loan period in years.
• Formula: Use provided formula for mortgage calculation.
• Input Validation: Implement error handling for valid inputs.
• Refinement: Break down code into modular functions for better readability and maintainability.

Final Notes

• Clean Code Practices: Write clean and maintainable code (use meaningful variable names, avoid magic numbers).
• Error Handling: Handle exceptions and validate user input appropriately.
• Further Learning: Enroll in complete Java series for in-depth knowledge and certification.
• Support: Like, share, and subscribe to support learning.

Conclusion

• Wrap-Up: Review essential concepts such as variables, data types, control flow, loops, and functions.
• Next Steps: Explore complex topics such as object-oriented programming, core Java APIs, and advanced features.