I know that we can write main method in abstract class, but what we can achieve from it ?
public abstract class Sample
{
public static void main(String args[])
{
System.out.println("Abstract Class main method : ");
}
}
We can not create the object of abstract class ,so what is the use of main method in abstract class ?
A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it. public abstract myMethod(); To use an abstract method, you need to inherit it by extending its class and provide implementation to it.
In any Java program, the main() method is the starting point from where compiler starts program execution. So, the compiler needs to call the main() method. If the main() is allowed to be non-static, then while calling the main() method JVM has to instantiate its class.
The main() method can appear in any class that is part of an application, but if the application is a complex containing multiple files, it is common to create a separate class just for main(). The main class can have any name, although typically it will just be called "Main".
Yes, abstract class can have Static Methods. The reason for this is Static methods do not work on the instance of the class, they are directly associated with the class itself.
Abstract just means you can't instantiate the class directly.
Loading a class is not the same as creating an instance of the class. And there's no need to create an instance of the class to call main(), because it's static. So there's no problem.
Abstract just means you can't instantiate the class directly. You can have constructors if you want - they might be needed for subclasses to initiate the object state. You can have static methods, including main() and they don't need an object so calling them is fine.
So you only got error when you try to create the object, which is when you run into the abstract limitation.
public abstract class Abstrc
{
Abstrc(){} // constructor
public abstract void run(); // abstract method
public static int mul(){return 3*2;} // static method
public static void main(String[] args)
{ // Static method that can be accessed without instantiation
System.out.println("Your abstract no is : " + Abstrc.mul());
}
}
Your abstract no is : 6
You can extend the abstract class and then the child class has a main
method without specifying one there.
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