What are the differences between the constructors and methods?

What is the output of the following Java program?

What is the output of the following Java program?

What is the output of the following Java program?

What is the static variable?

What is the static method?

What are the restrictions that are applied to the Java static methods?

Why is the main method static?

Can we override the static methods?

What is the static block?

Can we execute a program without main() method?