OOPS
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* Data Hiding
* Abstraction
* Encapsulation
* tightlyencapsulated class
* IS-A Relation
* Has-A Relation
* Method Signature
* Overloading
* Overriding
* Static Flow
* Instance flow
* Constructor
* Type casting
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Data Hiding
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our internal data shouldnt go out directly or outside person cant access our internal data.this oop feature is nothing but data hiding.(after authentication/validation we can access data)
 * by using private keyword we can achieve data hiding.(by decalring data member as private.)
 * Adv: Security