Union --> All rows/cols from 1st select and 2nd select with no duplicates Union All -->All rows/cols from 1st Select and 2nd Select with duplicates Intersect --> Rows common in both select statements...

The UNION operator is used to combine the result-set of two or more SELECT statements.   SQL joins are used to query data from two or more tables, based on a relationship between certain columns in these tables.

Methods cannot be overloaded only on the basis of return type atleast one argument should be different, otherwise compiler will give the message "The function is already defined in the class".

ya, methods can be overloaded based on the return type. You might be confused this with the Overriding. In method Overriding, it is not possible to change the return type, the entire prototype has to ...

The "==" operator can be used to test primitive values for equality, and can also be used to determine if two object references point to the same underlying object. For Java objects, the equals meth...

equals() method is expected to check for the equivalence the contents of the objects. Whereas the == operator is expected to check the actual object instances are same or not."j...