Naming convention and coding standard:

1. Class --> Demo, AudiCar, SortStudentByAge
2. Variable --> age, studentAge, noOfStudents
3. Methods --> work(), shiftGears(), checkEvenOrOdd()
4. Packages --> lowercase com, org, in…...
5. Constants --> Uppercase GST, PI, ID...

What is Java?

It is an Object Oriented Programming Language because it is support all 5 OOPS concept like Class, Object, Polymorphism, Inheritance, Abstraction and Encapsulation. What is object oriented means – without class we can’t write a single line of code. Types of Programming language.

Types -- Languages -- Concept support

Structured -- C, Python -- No OOPS concept support Object based -- VB, VB Script -- Class, Object Object Oriented -- C++, JAVA, C#, Python -- Class, Object, Polymorphism, Inheritance, Abstraction and Encapsulation

Features of JAVA:

1. Platform independent
2. Case Sensitive

Components of JAVA:

1. JDK – Java Development Kit
2. JRE – Java Runtime Environment
3. JVM – Java Virtual Machine

Operators:

Arithmetic Operator -> +, -, *, /, % Relational Operator ->>, >=, <, <=, ==, != Logical Operator ->&&, ||, ! Assignment/ Short hand operator -> = +=, -=, *=, /=, %= Increment/Decrement Operator -> ++, -- Ternary/Conditional Operator -> Variable = (Expression)? true: false; Operators are classified into 3 types Unary ->those operators we can use with single variable ++, --, +=,-=, *=, /=, %=, !, = Binary ->those operators we can use with at least two variables +, -, *, /, %, &&, ||, >, >=, <, <=, !=, == Ternary -> those operators we can use with at least three variables ?:

Conditional Statements:

Method Overloading:

In a class having multiple methods with the same name, but difference in arguments is called as Method Overloading. In order to achieve method overloading we need to satisfy either 1 of the following 3 rules.

1. There should be a change in the Number of Arguments.
2. There should be a change in the Data type of the Arguments.
3. There should be a change in the order/sequence of the Data types.

Note:

1. Both Static and Non-Static methods can be Overloaded.
2. Yes, we can overload Main() as well, But the execution starts from the main() which accepts String[] as the argument.
3. Return type might be same or different.
4. Method Overloading is also referred as Compile time Polymorphism.

Scanner

1. Scanner is a pre-defined class in java.util package.
2. Scanner class is used to accept dynamic input from the User.

Rules to accept dynamic input from the user (or) Rules to work around with Scanner class

1. Create an object of Scanner class.
2. Pass System.in to the Constructor call.

Syntax:

Scanner scan = new Scanner(System.in);

3. import Scanner class from java.util package.

Syntax: import java.util.Scanner;

4. Make use of pre-defined methods to accept dynamic input.