#43 Constructor in JAVA | Skyhighes | Lecture 43

Here's a comprehensive explanation of constructors in Java:

What are constructors?

Special methods: They are responsible for initializing the state of an object when it's created.
Same name as the class: They have the same name as the class they belong to, distinguishing them from regular methods.
No return type: They don't have a return type, not even void.
Purpose of constructors:

Initialization: To set initial values for the object's instance variables.
Resource allocation: To acquire resources like database connections or file handles that the object will need during its lifetime.
Preparation: To perform any other setup tasks necessary for the object to function properly.
Types of constructors:

Default constructor: A constructor with no arguments. If you don't explicitly define any constructors, Java provides a default constructor that does nothing.
Parameterized constructor: A constructor that takes one or more arguments to initialize the object's state with specific values.
How constructors are called:

Using the new keyword: Constructors are called using the new keyword followed by the class name and any required arguments:
Java
ClassName objectName = new ClassName(arguments);
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Example:

Java
class Person {
private String name;
private int age;

// Default constructor

public

Person()

{
this.name = "";
this.age = 0;
}

// Parameterized constructor

public

Person(String name, int age)

{
this.name = name;
this.age = age;
}
}
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Key points:

Every class has at least one constructor, even if you don't explicitly define it (the default constructor).
Constructors can be overloaded (multiple constructors with different parameter lists).
The this keyword is often used within constructors to refer to the current object being created.
Constructors cannot be inherited, but they can be called using super() from a subclass.
Understanding constructors is essential for creating and working with objects in Java. By effectively using constructors, you can ensure that objects are properly initialized and ready for use in your code.