Is calling java.lang.Object constructor really necessary?
java
Solution
It has to in order to satisfy section 4.9.2 of the JVM specification on structural constraints:
Each instance initialization method (§2.9), except for the instance initialization method derived from the constructor of class Object, must call either another instance initialization method of this or an instance initialization method of its direct superclass super before its instance members are accessed.
Now the rule could be relaxed for classes which are direct subclasses of `Object` - but I doubt that it would have any benefit, and would be inelegant (IMO). What if the `Object` constructor did perform some initialization in the future? Would you really want a spec which allowed you to bypass it?
Problem
I've recently installed bytecode outline Eclipse plugin and discovered that my Test class ``` public class Test { } ``` calls java.lang.Object's constructor ``` public class Test { public <init>()V L0 LINENUMBER 15 L0 ALOAD 0 INVOKESPECIAL java/lang/Object.<init>()V RETURN L1 LOCALVARIABLE this LTest; L0 L1 0 MAXSTACK = 1 MAXLOCALS = 1 } ``` `INVOKESPECIAL java/lang/Object.<init>()`V means calling java.lang.Object's constructor Does it make any sense? Judging by java.lang.Object bytecode ``` public <init>()V L0 LINENUMBER 37 L0 RETURN MAXSTACK = 0 MAXLOCALS = 1 ``` it's doing nothing. Just returns.