Mukesh S.

If a class contains only a private constructor and no other constructor, is it possible to create object of that class? If yes how?

Yes you can create Object of that class at anywhere by creating a public method that has the returned type as object and one more thing that Singleton pattern is nothing to do with creating an Object .The singleton Pattern we use is meant for one and only instance of that type in whole application consider the following code public class Alpha { private Alpha() { // no -args constructor } public Alpha createInstance() { return new Alpha(); } public static void main(String[]args) { Alpha a1= createInstance(); Alpha a2=createInstance(); } } Now If you want to create Object of Alpha class else where just make create Instance method as follow class Alpha { private Alpha() { // no -args constructor } public static Alpha createInstance() { return new Alpha(); } } public class Beta { public static void main(String[]args) { Alpha a1= Alpha.createInstance(); Alpha a2=Alpha.createInstance(); // Now check whether if those instance are same if(a1.equals(a2)) { System.out.println("Both instance are refering same object"); } else { System.out.println("Both instance are refering different object"); } } }

Which of the following will directly stop the execution of a Thread? A. wait() B.notify() C.notifyall() D.exits synchronized code

class HappyGarbage01 { public static void main(String args[]) { HappyGarbage01 h = new HappyGarbage01(); h.methodA(); /* Line 6 */ } Object methodA() { Object obj1 = new Object(); Object [] obj2 = new Object[1]; obj2[0] = obj1; obj1 = null; return obj2[0]; } } Where will be the most chance of the garbage collector being invoked? A. After line 9 B. After line 10 C. After line 11 D. Garbage collector never invoked in methodA()

Hello Shrikant who told you that you can explicity call garbage collector. You cann't call gc explicity even when you use System.gc() it is not guranteed that gc will be invoked it is all up to JVM when an object is eligible for garbage collection.even when you use finalise method that is a protected method of java.lang.Object class