NeilSys

If you see the error;

Error: no `server’ JVM at `C:\Program Files\Java\jre1.6.0\bin\server\jvm.dll’

There is a little trick to get the server JVM up and running:

Copy ‘server’ folder from the JDK’s JRE’s bin folder (example: C:\Program Files\Java\jdk1.6.0\jre\bin\server) and Paste the ‘server’ folder to JRE’s bin folder(example: C:\Program Files\Java\jre1.6.0\bin)

Done!

1. Constructor cannot return a value.
2. Interface cannot have constructor.
3. “A constructor cannot be abstract, static, final, native, strictfp, or synchronized”.
4. A constructor can be private.
5. Abstract class can have constructor.
6. A constructor can be overloaded.
7. Constructors are not members of a class. For this reason, constructors cannot be inherited; but can be accessed by a subclass. What does it mean? Constructors cannot be called with objects like d1.display(). To access a constructor create an object or access with subclass constructor (explicitly with super()).
8. Constructors are not inherited; only members (variables and methods) are inherited. So declaring a constructor final does not have any meaning as constructors cannot be overridden.
9. If a constructor is abstract, it cannot be implemented (cannot have body or no code). A constructor should have a body as constructor gives properties to an object at the time of creation itself.
10. Constructors are called when an object is created but cannot be called like a method (like d1.show()) with an object; so no necessity for a constructors to be static.
11. A constructor should not be synchronized as it locks the object in creation and thereby, as long as the object is not created no other object can be instantiated .
12. The methods which cannot be executed by JVM alone and depends on the underlying OS are known as native methods. Native methods execution is slow and for this reason many native methods throw a checked exception. Declaring a constructor native is unnecessarily inviting trouble and also a subclass constructor cannot call super class constructor easily.

A static initializer block will execute when a class is initialized — right after the class is loaded. This will happen (basically) the first time the class is referenced in the program. No instances need to be created. The static block will only be executed once (or in any case, only once each time the class is loaded.)

A constructor executes when, and only when, the “new” operator is used, or the Class.newInstance() or Constructor.newInstance() methods are called.

Moreover,

static block will execute first irrespective of if constructor is written or not.

order will always be static first and then constructor or any method.