🧩 Generics in Java – Type-Safe Code Simplified
What are Generics?
Generics in Java allow you to write type-safe and reusable code by enabling classes, interfaces, and methods to operate on objects of various types while providing compile-time type checking.
🔍 Why Use Generics?
Without generics:
With generics:
Benefits:
- Compile-time type checking
- No need for casting
- Code reusability
- Reduced runtime errors
🏗️ Generic Class Example
Usage:
⚙️ Generic Method Example
Usage:
🔐 Bounded Types
Limit generic types to a specific class hierarchy:
🌀 Wildcards in Generics
Wildcard | Use Case |
---|---|
<?> |
Unknown type |
<? extends T> |
Accepts T or its subclasses |
<? super T> |
Accepts T or its superclasses |
Example:
🧠 Summary
Generics help write robust, reusable, and type-safe code. They're widely used in Java Collections (like List<E>
, Map<K,V>
, etc.) and custom data structures.