Unit 1: Introduction to Java

Basics of Java

  • Java is a high-level, object-oriented programming language.
  • Java programs consist of classes and methods.

Hello, World!

  • The classic “Hello, World!” program in Java:
    public class HelloWorld {
        public static void main(String[] args) {
            System.out.println("Hello, World!");
        }
    }
    

Unit 2: Data Types and Operators

Primitive Data Types

  • int: Represents integers (e.g., -42, 0, 100).
  • double: Represents floating-point numbers (e.g., 3.14, 2.718).
  • char: Represents a single character (e.g., ‘A’, ‘$’).
  • boolean: Represents true or false.

Variables and Assignment

  • Declare and assign a variable:
    int age = 25;
    double pi = 3.1415;
    char grade = 'A';
    boolean isStudent = true;
    

Arithmetic Operators

  • Basic arithmetic operators:
    • Addition: +
    • Subtraction: -
    • Multiplication: *
    • Division: /
    • Modulo: %

Comparison Operators

  • Comparison operators return boolean values:
    • Equal to: ==
    • Not equal to: !=
    • Greater than: >
    • Less than: <
    • Greater than or equal to: >=
    • Less than or equal to: <=

Logical Operators

  • Logical operators for combining conditions:
    • AND: &&
    • OR: ||
    • NOT: !

Conditional Statements

  • if statement:
    if (condition) {
        // Code to execute if the condition is true
    }
    
  • else statement:
    if (condition) {
        // Code to execute if the condition is true
    } else {
        // Code to execute if the condition is false
    }