You are designing a BankAccount class with a private balance field. Which design correctly allows controlled access to balance?
hard📝 Application Q8 of 15
Java - Encapsulation
You are designing a BankAccount class with a private balance field. Which design correctly allows controlled access to balance?
AProvide public methods to deposit, withdraw, and get the balance, keeping <code>balance</code> private.
BMake <code>balance</code> public so other classes can modify it directly.
CProvide only a public setter method for <code>balance</code> without a getter.
DMake <code>balance</code> protected and access it directly from other classes.
Step-by-Step Solution
Solution:
Step 1: Understand encapsulation
Private fields should be accessed via controlled public methods.
Step 2: Evaluate options
Provide public methods to deposit, withdraw, and get the balance, keeping balance private. provides methods to safely modify and read balance, enforcing rules.
Step 3: Problems with other options
Public or protected fields allow uncontrolled access, risking data integrity.
Final Answer:
Provide public methods to deposit, withdraw, and get the balance, keeping balance private. -> Option A
Quick Check:
Encapsulation requires private fields and public methods [OK]
Quick Trick:Use private fields with public methods for control [OK]
Common Mistakes:
Making fields public for easy access
Providing setters without validation
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