In Java, constructor overloading allows a class to have multiple constructors with different parameters. This enables us to create objects of the same class using different sets of input values. When a constructor is overloaded, each constructor can perform different initialization tasks depending on the arguments passed.

Syntax

public class ClassName {
    
    // Constructors
    
    public ClassName() {
        // Default constructor code
    }
    
    public ClassName(type1 param1) {
        // Constructor code
    }
    
    public ClassName(type2 param2) {
        // Constructor code
    }
    
    // Additional constructors
    
    // ...
}

Example

Let’s consider the example of a Person class that represents a person’s information, such as their name and age. We can define different constructors to initialize the object based on different input parameters.

public class Person {
    
    private String name;
    private int age;
    
    public Person() {
        name = "Unknown";
        age = 0;
    }
    
    public Person(String personName) {
        name = personName;
        age = 0;
    }
    
    public Person(String personName, int personAge) {
        name = personName;
        age = personAge;
    }
    
    // Other methods
    
    //...
}

In the example above, the Person class has three constructors:

1. The default constructor sets name to “Unknown” and age to 0.
2. The constructor with a single parameter personName sets name to the specified value and age to 0.
3. The constructor with two parameters personName and personAge sets both name and age to the specified values.

We can now create Person objects based on the required parameters:

Person person1 = new Person(); // Using the default constructor
Person person2 = new Person("John"); // Using the constructor with a single parameter
Person person3 = new Person("Alice", 25); // Using the constructor with two parameters

By overloading the constructors, we provide flexibility to create objects with varying initializations depending on the requirements.

#Java #Constructors