Chapter 4 : Class & Object properties

 

 

Java is a versatile and powerful programming language that enables developers to create robust, high-performance applications. Java is compiled into bytecode, which can be run on any platform that supports the Java Virtual Machine (JVM).

 

One of the key advantages of Java is its portability - programs written in Java can be run on any platform that supports the JVM. This means that Java programs can be easily deployed across a wide range of devices and systems.

 

Java is also a highly versatile language, supporting a wide range of data types. This versatility enables developers to create rich and complex applications.

 

Finally, Java supports a number of control statements and loops, which allows for the creation of sophisticated algorithms. These features make Java an ideal choice for developing high-performance applications.

 

In summary, Java is a powerful and versatile programming language that enables developers to create robust, high-performance applications. Java's portability and data type support make it an ideal choice for developing sophisticated applications.

 

Chapter 4 : Class & Object properties

 

In Java, a class is a template for creating objects. A class defines the variables and methods that make up an object.

 

Each object created from a class inherits the variables and methods of that class. This inheritance enables objects to share common properties and behaviours.

 

In addition, a class can define special methods called constructors. A constructor is used to initialize an object when it is first created.

 

Finally, a class can also define a finalize() method. This method is called when an object is about to be destroyed. It can be used to clean up any resources that the object was using.

 

The following example shows a simple class definition:

 

 

 

class MyClass {

 

int x;

 

public MyClass() {

 

x = 0;

}

}

 

 

In this example, the class MyClass defines a single variable, x. The class also defines a constructor, which initializes the value of x to 0.

 

In order to use a class, you first need to create an instance of that class. An instance is an individual object that has been created from a class.

 

The following example shows how to create an instance of the MyClass class:

 

 

 

MyClass myObj = new MyClass();

 

 

In this example, we create an instance of the MyClass class and assign it to the variable myObj. We can then access the properties and methods of myObj just like any other object.

 

Java also supports inner classes. An inner class is a class that is defined within another class. Inner classes have access to the variables and methods of the outer class.

 

Inner classes are often used to represent objects that are part of a larger object. For example, an inner class could be used to represent the wheels of a car.

 

The following example shows how to define an inner class:

 

 

 

class MyClass {

 

int x;

 

class MyInnerClass {

public void printX() {

System.out.println(x);

}

}

}

 

 

In this example, we have defined an inner class called MyInnerClass. This class has access to the variable x from the outer class. We can create an instance of the inner class as follows:

 

 

MyClass myObj = new MyClass();

MyClass.MyInnerClass myInnerObj = myObj.new MyInnerClass();

 

myInnerObj.printX();

 

 

In this example, we create an instance of the inner class and assign it to the variable myInnerObj. We can then call the printX() method on myInnerObj, which will print the value of x from the outer class.

 

Java also supports static methods and variables. A static method is a method that is associated with a class, rather than an instance of that class.

 

A static method can be invoked without creating an instance of the class. Static methods are often used to provide utility methods, such as mathematical functions.

 

The following example shows how to define a static method:

 

 

class MyClass {

 

static int x = 5;

 

public static void printX() {

System.out.println(x);

}

}

 

 

In this example, we have defined a static method called printX(). We can call this method without creating an instance of the MyClass class, as follows:

 

 

MyClass.printX();

 

 

In addition to static methods, Java also supports static variables. A static variable is a variable that is associated with a class, rather than an instance of that class.

 

Static variables are often used to represent constants, such as mathematical pi. The following example shows how to define a static variable:

 

 

 

class MyClass {

 

static final double pi = 3.14;

 

}

 

 

In this example, we have defined a static variable called pi. This variable represents the mathematical constant pi. We have also declared pi to be final, which means that it cannot be changed.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass() {

this(0); // calls the other constructor in this class with value 0.

}

 

public int getX() { // Accessor method for x. Returns the value of x.

return x; // No parameters are required. } }

 

 

In this example, we have defined a method called getX(). This method returns the value of the x variable.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass();

myObj.getX(); // Will return 0

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return the value of x.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

 

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

 

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

 

 

The following example shows how to define a method that returns an object:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

 

 

The following example shows how to define a method that returns an object:

 

 

 

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

return this; // Returns the current instance of the class. } }

 

 

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that return objects. A method can return any type of object, including an instance of a class.

 

 

 

The following example shows how to define a method that returns an object:

 

 

 

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public MyClass getX() { // Method that returns an object.

 

return this; // Returns the current instance of the class. } }

 

 

In this example, we have defined a method called getX(). This method returns the current instance of the class. We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.getX(); // Will return an object of type MyClass

 

 

In this example, we have used the getX() method to create an instance of MyClass. We can then call the getX() method on myObj, which will return an object of type MyClass.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

Java also supports methods that take objects as parameters. A method can take any type of object, including an instance of a class.

 

The following example shows how to define a method that takes an object as a parameter:

 

 

class MyClass {

 

int x;

 

public MyClass(int i) {

x = i;

}

 

public void printX(MyClass obj) { // Method that takes an object as a parameter.

System.out.println(obj.x); // Will print the value of the x variable from the object that is passed in. } }

 

 

 

 

In this example, we have defined a method called printX(). This method takes an object of type MyClass as a parameter. The method will then print the value of the x variable from the object that is passed in.

 

We can then use this method to create an instance of MyClass and assign it to the variable myObj, as follows:

 

 

MyClass myObj = new MyClass(5);

myObj.printX(myObj); // Will print 5

 

 

In this example, we have used the printX() method to create an instance of MyClass. We can then call the printX() method on myObj, which will print the value of x from myObj.

 

 

 

Comments