- Generics - Home
- Generics - Overview
- Generics - Environment Setup
- Examples - Generic Classes
- Generics - Generic Classes
- Type Parameter Naming Conventions
- Generics - Type inference
- Generics - Generic Methods
- Generics - Multiple Type Parameters
- Generics - Parameterized Types
- Generics - Raw Types
- Examples - Bounded Type Parameters
- Bounded Type Parameters
- Generics - Multiple Bounds
- Examples - Collections
- Generics - Generic List
- Generics - Generic Set
- Generics - Generic Map
- Examples - Wild Cards
- Upper Bounded Wildcards
- Generics - Unbounded Wildcards
- Lower Bounded Wildcards
- Generics - Guidelines for Wildcards
- Type Erasure
- Generics - Generic Types Erasure
- Generics - Bound Types Erasure
- Unbounded Types Erasure
- Generics - Generic Methods Erasure
- Restrictions on Generics
- Generics - No Primitive Types
- Generics - No Instance
- Generics - No Static field
- Generics - No Cast
- Generics - No instanceOf
- Generics - No Array
- Generics - No Exception
- Generics - No Overload
- Generics Useful Resources
- Generics - Quick Guide
- Generics - Useful Resources
- Generics - Discussion
Java Generics - No instanceOf
Because compiler uses type erasure, the runtime does not keep track of type parameters, so at runtime difference between Box<Integer> and Box<String> cannot be verified using instanceOf operator.
Box<Integer> integerBox = new Box<Integer>();
//Compiler Error:
//Cannot perform instanceof check against
//parameterized type Box<Integer>.
//Use the form Box<?> instead since further
//generic type information will be erased at runtime
if(integerBox instanceof Box<Integer>){ }
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