Java
/
OOP
- 1 Basics 9
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Classes S
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Objects S
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Arrays S
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Variables S
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Loops S
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Numbers S
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Strings S
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Exceptions S
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Regexp S
- 2 OOP 9
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Inheritance
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Polymorphism
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Static S
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Abstract
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Interfaces
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Constructors S
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Packages
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Nested Classes
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Final
- 3 Compiler 2
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Sublime Text S
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Apache Ant
- 4 Collections 8
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Lists
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Comparable S
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Sets
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Maps
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Generics
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Properties
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Streams
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Json
- 5 Threads 4
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Create Thread S
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Sleep
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Lock
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Scheduler
- 6 Design Patterns 4
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Singleton
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Observer
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Strategy
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Mediator
- 7 Swing 12
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Frame
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Panel
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Listener
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Combo Box
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Label
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Image
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Menu
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Table
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Layout
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Drawing
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Timer
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Designer
- 8 I/O 7
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Streams IO
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Socket
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Watching Files
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Mail
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Logger
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Clipboard
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Encrypt S
- 9 Effective 7
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Constructors S
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Dependency Injection
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Composition
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Interfaces Default
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Import Static S
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Enums
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Lambdas
- 10 Junit 5
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About Junit S
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Test Case
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Suite Test
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Annotations
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Exceptions
- 11 Lambdas 7
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Expressions S
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Functional Interfaces
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Streams
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Common Operations
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Default Methods
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Static Methods S
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Single Responsibility
- 12 JavaFX 6
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Openjfx
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Scene Builder
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First App
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Jar Archive
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On Action
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Change Listener
- 13 Maven 4
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Demo
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Spring Boot
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Junit
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Guava
- 14 Spring Boot 8
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Quick start S
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Rest service
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Consuming Rest
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Templates
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Security
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Command Line
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Scheduling Tasks
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Ajax
R
Q
Encapsulation
Java allows a class within another class (nested classes).
/**
* Nested classes increases encapsulation.
* They can lead to more readable and maintainable code.
*/
package com.minte9.oop.nested_classes;
public class Encapsulation {
public static void main(String[] args) {
System.out.println(
OuterClass.InnerClass.y // 20
);
}
}
class OuterClass {
int x = 10;
static class InnerClass {
static int y = 20;
}
}
Static
The nested classes are the only classes that can be declare static.
/**
* Only nested classes can be declared as static classes.
* Inner classes can use fields from outer class.
*/
package com.minte9.oop.nested_classes;
public class Static {
public static void main(String[] args) {
A.B.run(); // 10
}
static class A {
static int a = 10;
static class B {
public static void run() {
System.out.println(a); // field from Outer Class
}
}
}
}
➥ Questions
Last update: 227 days ago