I have a query related to new keyword.
1. What is the difference between
new Demo().abc();
and
Demo demo=new Demo();
demo.abc();
demo=null;
2. If I use first one then automatically garbage collector remove the memory?
My Question is:
how to remove memory for the below object:
new Demo().abc();
Case -1 :
new Demo().abc();
Here, we are not maintaining any explicit reference to the newly created Demo instance. But inside the abc(), the this reference will point to the newly created instance. So, if the reference doesn't leak from abc(), as soon as the method returns, the newly created Demo instance will be ready for GC (As it becomes unreachable from any thread).
If there is a reference leak like this :
public void abc()
{
someOtherMethod(this); // starts another thread and does something else
...
}
In the above case, even when abc() returns, the Demo instance created could still be reachable and thus will not be eligible for GC.
Case -2 :
Demo demo=new Demo();
demo.abc();
demo=null;
Here as soon as you set demo to null and assuming abc() doesn't leak the reference of demo to some other thread, your demo instance will become unreachable as soon as you set it to null and thus, it will be eligible for GC.
You don't have explicitly do anything to remove "new Demo().abc()" ,generally as long as there are no strong references to this Demo() object it'll get Garbage Collected by JVM.
