Equals vs ==

1. == Is used to compare reference and equals is used to compare the contents.

2. == We can used with primitive type, when we used == with primitive types(data types) it will work as comparing two values. But equals we can not used for primitives type as it is method declared in object class. In short all the classes in java having own equals method.

3. If we call equals on reference variable who have null value, then we will get nullpointerexception.

Example

String s;

S.equals("Abc")

It will throw nullpointerexception.

4. Equals is a method which is in object class. Object class is extended by all the classes in java. So in short equals method is contained by all the classes in java.