Java Generics Tutorial
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- Java Generics - Discussion
- Java Generics - Useful Resources
- Java Generics - Quick Guide
- Java Generics - No Overload
- Java Generics - No Exception
- Java Generics - No Array
- Java Generics - No instanceOf
- Java Generics - No Cast
- Java Generics - No Static field
- Java Generics - No Instance
- Java Generics - No Primitive Types
- Java Generics - Methods Erasure
- Unbounded Types Erasure
- Java Generics - Bound Types Erasure
- Java Generics - Types Erasure
- Generics - Guidelines for Wildcards
- Lower Bounded Wildcards
- Generics - Unbounded Wildcards
- Upper Bounded Wildcards
- Java Generics - Generic Map
- Java Generics - Generic Set
- Java Generics - Generic List
- Java Generics - Multiple Bounds
- Bounded Type Parameters
- Java Generics - Raw Types
- Java Generics - Parameterized Types
- Java Generics - Multiple Type
- Java Generics - Generic Methods
- Java Generics - Type inference
- Type Parameter Naming Conventions
- Java Generics - Generic Classes
- Java Generics - Environment Setup
- Java Generics - Overview
- Java Generics - Home
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Unbounded Types Erasure
Java Generics - Unbounded Types Erasure
Java Compiler replaces type parameters in generic type with Object if unbounded type parameters are used.
Example
package com.tutorialspoint; pubpc class GenericsTester { pubpc static void main(String[] args) { Box<Integer> integerBox = new Box<Integer>(); Box<String> stringBox = new Box<String>(); integerBox.add(new Integer(10)); stringBox.add(new String("Hello World")); System.out.printf("Integer Value :%d ", integerBox.get()); System.out.printf("String Value :%s ", stringBox.get()); } } class Box<T> { private T t; pubpc void add(T t) { this.t = t; } pubpc T get() { return t; } }
In this case, java compiler will replace T with Object class and after type erasure,compiler will generate bytecode for the following code.
package com.tutorialspoint; pubpc class GenericsTester { pubpc static void main(String[] args) { Box integerBox = new Box(); Box stringBox = new Box(); integerBox.add(new Integer(10)); stringBox.add(new String("Hello World")); System.out.printf("Integer Value :%d ", integerBox.get()); System.out.printf("String Value :%s ", stringBox.get()); } } class Box { private Object t; pubpc void add(Object t) { this.t = t; } pubpc Object get() { return t; } }
In both case, result is same −
Output
Integer Value :10 String Value :Hello WorldAdvertisements