As i know, String objects are immutable. yes it is 100% true. then why concat operation performed on String.
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left side of == concat two string object(a and b)results into a 3rd new object lets say x,and right side of == also concat two string object(a and b)results into a fourth new object lets say y. ......... then dear both x and y two different object created in memory....hence == operator returns false...