Hi Laxmi,
From Java API�s Object class description�
The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).
As (sb1= = sb2) returns false, sb1.equals(sb2) also returns false.which is also applicable to sb1&ss1.