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
  }