OOP · 1 min · daily challenge of 2026-11-02
How the decorator pattern wraps objects
See how decorators implement the same interface and delegate calls, using Java's BufferedReader wrapping a FileReader as an example.
The quiz
Which pattern adds behaviour to an object by wrapping it in another object with the same interface?
- Template method
- Factory
- Singleton
- Decorator
Show the answer
D. Decorator
Transcript
Is daily challenge question ne design patterns par sabko soch mein daal diya.
Decorator wrapped object ka same interface implement karta hai, uska reference rakhta hai, aur method calls delegates karke behaviour jodta hai.
Yahan BufferedReader wrapped FileReader ko wrap karta hai, jab tum read call karte ho, toh yeh delegates karke buffering ka extra logic jodta hai.
Yahi asli baat hai, client jab method calls karta hai, toh decorator use intercept karke delegates karta hai aur naya feature chupchap jod deta hai.
Teen niyam yaad rakho, pehla same interface share karna, doosra wrapped object ko delegation karna, aur teesra bina core logic badle behaviour add karna.
Screen par sawal dekho, kaun sa pattern object ko same interface mein wrap karke behaviour jodta hai, pause karo aur sahi answer chuno.
Sahi answer D Decorator hai, kyonki yeh wrapping aur delegation istemaal karta hai, jabki Singleton sirf single instance banane ka kaam restrict karta hai.
Decorator pattern ko exam se pehle revise karne ke liye yeh summary save karo, aur InternDoor par daily challenge questions practice karte raho.
