Java programming

2. Introduction

3. Scenario based Question
- Imagine a situation where we need to collect the names of 50 students
- How will you write a Java program to do this?
- Yes! You will introduce 50 new variables and collect the data
But is that way an efficient one?

4. Arrays
What is Arrays?
- group of elements
- same Datatype

5. • One-Dimensional Array
• Two (or) Multi-Dimensional Array
Array - Types

6. • 1D -> only one row
• 2D -> multiple number or rows and coloumns
1D vs 2D Array

7. Mapping of Arrays

8. Which mapping of 2D Arrays is right?
0,0 0,1 0,2
1,0 1,1 1,2
2,0 2,1 2,2
Row 0 Row 1
col 0 col 1 col 0 col 1

9. • Do we have any other type of Array?
• Yes! It is Jagged Array

10. • Arrays of Arrays
• Column number is different in each and every rows
Jagged Array

11. • Fetch date from client machine and store in server
• Ex: In gmail, we have the last logged in activity in our Activity log
Date and time

12. • Consider we are attending an Online exam
• Is there any possibilities to cheat during the exam?
• Yes! By changing the time in the client machine.
• Ex: Hotstar
Realtime example

13. • Association is the OOPS concept to define the relationship
between objects.
• It can be
- one –to-one
- one-to-many
- many-to-one
- many-to-many
Association

14. • It provide the relationship between two classes.
• Has-A relationship.
• contains the reference of another class and gives ownership to that class.
Aggregation

15. class Subject
{
private String name;
public void setName(String name)
{
this.name = name;
}
public String getName()
{
return name;
}
}
public class Student {
private Subject[] studyAreas = new Subject[10];
//the rest of the Student class
}
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16. Interface
• collection of abstract methods.
• to overcome multiple inheritance.
• achieve loose coupling.

18. Packages
• mechanism to encapsulate a group of classes, sub packages and
interfaces
• A default member (without any access specifier) is accessible by
classes in the same package only.

19. Packages - types
• User-Defined packages
• the built-in package ( java.lang, util, awt, javax, swing, net, io, sql etc)

20. Exceptions
• Used to handle runtime error
• Interrupts the normal flow of execution.
• They are represented in two ways
• Error
• Exception

21. THANK YOU