nirjari patel wrote:If so, then every object will carry unique hashcode, right ?
No,
you should never assume that every object has a unique hash code. A hash code is not a unique identifier of an object.
It's easy to see why that's not possible. A hash code is a 32-bit integer. That means that there are 2^32 = 4,294,967,296 possible hash codes.
Now, let's look at strings of exactly 10 letters (A-Z). There are 26^10 = 141,167,095,653,376 possible combinations of 10 letters. That's much more than the number of possible hash codes. So there must be lots of different 10-letter strings that have the same hash code.
The most important thing to remember is that when two objects are equal (the equals() method returns true for those two objects), then the hash code of those objects must be the same.
Note that this works only in one direction: the converse (hashcodes are equal => objects are equal) does not hold. It is allowed for two objects to be not equal, but have the same hash code.