techrajdeep/JavaForBeginners

java string

1. more flexible and reusable

2. Encapsulation--> hiding the data , accessing the data using only method

3. Abstraction--> Hiding the implementation

5. Without perform upcast if we try to downcast , ClassCastException will be thrown.

          It is a runtime exception or unchecked exception.
          It is class, present in java.lang package.
          It can be avoided by using a operator known as ‘instanceof’.
   

6. Child ---(extends)--->Parent Parent p=new Child(); //auto downcasting Child c=new (Child)p;//Explicit upcasting

7. Data types int i= short// valid, no truncation int i = long //there will be truncation //error int i =(int)long;//explicit casting

8. BigDecimal bdl=new BigDecimal("22.55688");