How to create constructor overloading in java Program -

class Language
{
    String name;

    // Constructor method
    Language()
    {
        System.out.println("Constructor method called.");
    }

    // Constructor with parameter
    Language(String t)
    {
        name = t;
    }

    public static void main(String[] args)
    {
        Language cpp = new Language();
        Language java = new Language("Java");

        cpp.setName("C++");

        java.getName();
        cpp.getName();
    }

    // Method to set the name
    void setName(String t)
    {
        name = t;
    }

    // Method to get the name
    void getName()
    {
        System.out.println("Language name: " + name);
    }
}

1. Class Declaration:

public class Language {

String name;

A class called Language is defined by an instance variable name of type String. This variable will store the name of the programming language.

2. Constructors:

Language() {

System.out.println(“Constructor method called.”);

}

Language(String t) {

name = t;

}

Default Constructor (Language()): It does not accept any arguments, just prints the “Constructor method called.” when the object is declared using this constructor.
Parameterized Constructor (Language(String t)): It accepts a String type variable t and it assigns the value to the name variable of the object. So one can set the name variable right after the declaration of the object.

3. Main Method:

public static void main(String[] args) {

Language cpp = new Language();

Language java = new Language(“Java”);

cpp.setName(“C++”);

java.getName();

cpp.getName();

}

Creating cpp Object via Default Constructor:

Language cpp = new Language(); creates an object of the Language class via default constructor.

The default constructor prints “Constructor method called.” to the console because it gets called at object creation time.

Creating java Object via Parameterized Constructor :

Langauge java = new Langauge(“Java”); creates another object of the Langauge class, but this time it uses a parameterized constructor.

The name of the java object is set to “Java” when the object is created.

Setting the name of the cpp Object using setName() Method:

cpp.setName(“C++”);

invokes the setName() method on the cpp object and sets the name of cpp to “C++”.

Obtaining java Object’s name Using getName() Method:

java.getName(); invokes the getName() method on the java object, which prints “Language name: Java” to the console.

Obtaining cpp Object’s name Using getName() Method:

cpp.getName(); invokes the getName() method on the cpp object, which prints “Language name: C++” to the console.

4. Methods:

void setName(String t) {

name = t;

}

void getName() {

System.out.println(“Language name: ” + name);

}

There are the following methods:

setName(String t) : This method sets the name variable of the object to the value passed in the parameter t.
getName() : This method prints the current value of the name variable to the console.

Step-by-Step Execution:

1. Creating cpp Object:

Language cpp = new Language(); This creates a Language object using the default constructor.

The constructor prints “Constructor method called.”.

2. Creating java Object:

Language java = new Language(“Java”); creates a Language object using the parameterized constructor, setting name to “Java”.

3. Calling setName(“C++”) on cpp Object:

cpp.setName(“C++”); changes the name of the cpp object to “C++”.

4. Calling getName() on java Object:

java.getName(); prints the name of the java object, which is “Java”.

Output: “Language name: Java”

5. Calling getName() on cpp Object:

cpp.getName(); prints the name of the cpp object, which is “C++”.

Output: “Language name: C++”

Output:

Constructor method called.

Language name: Java

Language name: C++

Summary:

Constructor: The program has two constructors: a default constructor and a parameterized constructor. The default constructor prints “Constructor method called.”, and the parameterized constructor sets the name of the object.
Methods: There are two methods: setName() (to set the name of an object) and getName() (to print the name of an object).
Object Instantiation: There are two objects, namely cpp and java, created: one with the default constructor and the other with the parameterized constructor.
Output: It prints the names of the programming languages, which would include the output “Java” and “C++”, using the getName() method.