Question

What does public static <X> void main(String[] args) stand for? I tried to understand but didn’t get. I know about public static void main(String[] arg).
Thanks in advance.

Answer 1

Let’s look at each bit in turn:

• public – it’s a public method, accessible to anything which has access to the class in which this is declared
• <X> – this is (somewhat bizarrely) a generic method with an unbound type variable X
• static – the method is related to the type in which it’s declared, not any specific instance of the type
• void – the method doesn’t return a value
• main – the name of the method
• String[] args – a single parameter, of type String[] and called args

main is the entry point used by the JVM. When you run:

java foo.bar.Baz

it will try to find a main method in class foo.bar.Baz. I’ve never seen a generic main method before, admittedly. For more about generics in Java, read the Java Generics FAQ.