Difference between zero argument constructor and default constructor in Java?

Default Constructor:**

• A constructor that is automatically provided by the Java compiler when no constructor is defined in the class.
• It has no parameters (zero-arguments) and no body code.
• It initializes instance variables to default values (e.g., 0 for int, null for objects).

Example:

public class MyClass {

}

Zero-Argument Constructor:

• A constructor that is explicitly written by the programmer with no parameters.
• It has no parameters, it is not considered a default constructor, because it's written by developer. Example:

public class MyClass {
    MyClass() {
        System.out.println("zero-argument constructor");
    }
}

This:

• This is a keyword.
• This refers to current object.It is used to define global variable.
• This keyword is used to differentiate between local and global variable.
• When local variable names are the same as instance variables, this is used to differentiate.

Example:

public class Student {
    String name;

    public Student(String name) {
        this.name = name; 
    }
}

Package:

In java package means folder.

Why Use Packages in Java?

• Grouping similar file.
• Avoid naming conflict.

Create package:
package com.indianBank;

Compile package:
javac -d . classname.java

Run package:
java filename