Modifiers are an important part of the Java programming language and allow developers to control what level of access other classes have to their code. The four basic modifier types in Java are public, private, protected, and default (also known as package-private).
● Public: Public modifiers allow any class within your program or even outside it access your code - giving you full flexibility over how data is shared across different applications.
● Private: Private modifiers restrict access to only the methods inside a single class, while protected gives external classes access but only if they’re subclasses of that particular class.
● Default: Default (package-private) allows all other classes within the same package to use your methods but not those from outside packages - helping ensure proper encapsulation of data at runtime.
● Protected: A protected variable, method, or class can be accessed from the same package or a subclass in a different package.
Example:
class Car {
public int speed;
protected String colour;
int year;
private String make;
}
"Car" has four variables, two of them (speed and year) are public, one of them (color) is protected, and one of them (make) is private.
Non-access modifiers
The following are the non-access modifiers:
● Static: A static variable or method belongs to the class rather than an instance of the class.
● final: A final variable or method cannot be modified once it is initialized.
● Abstract: An abstract method does not have an implementation and must be overridden in a subclass.
● synchronized: A synchronized method can only be accessed by one thread at a time.
● transient: A transient variable is not included in the serialization process
Example:
class Car {
public static int numberOfCars;
public final int MAX_SPEED = 120;
public abstract void startEngine();
public synchronized void accelerate() {
// code to accelerate
}
private transient int secretNumber;
} In this example, the class "Car" has one static variable "numberOfCars" of type int, one final variable "MAX_SPEED" of type int, one abstract method "startEngine", one synchronized method "accelerate" and one transient variable "secretNumber".
When creating applications with Java, it is important to understand how each type of modifier works and when best used for each situation. Depending on what kind of security needs there are for a given application, developers can choose which protection levels should be applied during development by selecting from one or more modifier types available. This helps maintain integrity by preventing sensitive information from being accessed accidentally while still allowing necessary resources, such as libraries or data sources, to be freely shared amongst multiple programs without compromising user privacy! Knowing when to use correct modifiers can make all the difference between an efficient piece of software and something vulnerable, so understanding their purpose is essential for successful coding in this language!
