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:
%
- Addition:
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:
<=
- Equal to:
Logical Operators
- Logical operators for combining conditions:
- AND:
&&
- OR:
||
- NOT:
!
- AND:
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 }