Java development

2. Access Modifiers
Helps to restrict the scope of a class, constructor , variable , method or data
member.
Types
• Public
• Private
• Protected
• Default

3. Real time example
Bed Room
Hall
Reception
Door Step
Producted and default
Public
Private

4. Real time application

5. Public

6. Public
• The public access modifier is specified using the keyword public.
• The members, methods and classes that are declared public can be
accessed from anywhere.

7. //Predict the output
package one;
public class A
{
public void display()
{
System.out.println("Java");
}
}
import one.*;
class B
{
public static void main(String args[])
{
A obj = new A;
obj.display();
}
}
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8. //Creating Packing countdigits
package countdigits;
public class First
{
public void no_of_digits()
{
int count = 1;
while(num>0){
num=num/10;
count++;
}
System.out.print(count);
}
}
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9. //Predict the output
import countdigits.*;
class Second
{
public static void main(String args[])
{
First obj = new First();
obj.no_of_digits(456);
}
}
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10. //Predict the output
class Log{
public int debugLevel = 1;
public void debug(String logLine){
System.out.println("Debug: "+logLine);
}
public void info(String logLine){
System.out.println("Information: "+logLine);
}
}
public class Main{
public static void main( String[] args ) {
Log log = new Log();
log.debug("debug with level " + log.debugLevel);
log.debugLevel = 5;
log.info("information with level " + log.debugLevel);
}
}
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11. Private

12. Private
• The private access modifier is specified using the keyword private.
• The methods or data members declared as private are accessible
only within the class in which they are declared.

13. //Predict the output
class A{
private double num = 100;
private int add(int a,int b){
return a+a;
}
}
public class Example{
public static void main(String args[]){
A obj = new A();
System.out.println(obj.num);
System.out.println(obj.add(10,20));
}
}
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14. //Predict the output
public class PersonalData {
private String name;
public String getName() {
return this.name;
}
public void setName(String name) {
this.format = name;
}
}
public class UnknownPerson {
Public static void main(String[] main){
PersonalData d = new PersonalData();
d.setName(“Mansoor”);
System.out.println(d.getName());
}
}
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15. //Predict the output
class Data
{
private String name;
public String getName(){
return this.name;
}
public void setName(String name)
{
this.name = name;
}
}
public class Main
{
public static void main(String[] main)
{
Data d = new Data();
d.setName("Focus");
System.out.println(d.getName());
}
}
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16. Protected

17. Protected
• The protected access modifier is specified using the keyword protected.
• It can be accessed within the same package classes and sub-class of any
other packages.

18. //Predict the output
package package1;
public class Product {
protected int multiplication(int a, int b){
return a*b;
}
}
package package2;
import package1.*;
class Test extends Product{
public static void main(String args[]){
Test obj = new Test();
System.out.println(obj.multiplication(11,10));
}
}
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19. //Predict the output
class Logger
{
protected void debug(String logLine)
{
System.out.println("Debug line: "+logLine);
}
}
public class Main extends Logger
{
public static void main(String [] args)
{
Main logger = new Main();
logger.debug("Main method executed");
}
}
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20. Default
• The data members, class or methods which are not declared using any
access modifiers.
• It is accessible only within the same package.

21. //Predict the output
class Logger
{
void message()
{
System.out.println("This is a default");
}
}
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22. //Predict the output
package package1;
public class Product {
int multiplication(int a, int b){
return a*b;
}
}
package package2;
import package1.*;
class Test {
public static void main(String args[]){
Product obj = new Product();
System.out.println(obj.multiplication(11,10));
}
}
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23. Access Modifiers Visibility
Public Visible to All classes.
Private
Visible with in the class. It is not accessible outside the
class.
Protected
Visible to classes with in the package and the subclasses
of other package.
No Access Modifier (Default) Visible to the classes with the package

24. THANK YOU