What is Type Casting in Java - Casting one Class to other class or interface Example

Type casting in Java is to cast one type, a class or interface, into another type i.e. another class or interface. Since Java is an Object oriented programming language and supports both Inheritance and Polymorphism, It’s easy that Super class reference variable is pointing to Sub Class object but catch here is that there is no way for Java compiler to know that a Super class variable is pointing to Sub Class object. Which means you can not call method which is declared on sub class. In order to do that, you first need to cast the Object back into its original type. This is called type-casting in Java. This will be more clear when we see an example of type casting in next section. Type casting comes with risk of ClassCastException in Java, which is quite common with method which accept Object type and later type cast into more specific type. we will see when ClassCastException comes during type casting and How to avoid it in coming section of  this article. Another worth noting point here is that from Java 5 onwards you can use Generics to write type-safe codeto reduce amount of type casting in Java which also reduces risk of java.lang.ClassCastException at runtime.

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Posted by bandrux

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