1. Question 1 – Making instance variables private

• ❌ is an application of security and protects against hackers

• ❌ is an application of abstraction & protects behaviors

• ❌ is a requirement of Java

• ✔️ is an application of abstraction and protects against object users gaining direct access to object state.

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2. Question 2 – Method that changes instance variables

• ❌ constructor

• ❌ default constructor

• ❌ accessor method

• ✔️ mutator method

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3. Question 3 – Correct constructors for class Vehicle

Correct options:

• ✔️ public Vehicle(){}

• ✔️ public Vehicle(double mileage, int year){ this(mileage); this.year = year; }

Incorrect:

• ❌ public void Vehicle(...) → has return type → NOT a constructor

• ❌ public makeVehicle(...) → name mismatch

• ❌ uses odometer = odometer; (wrong — should use this.odometer)

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4. Question 4 – When a constructor is written

• ✔️ the default constructor is no longer available

• ✔️ the default constructor must be recreated if needed

• ❌ the default constructor cannot be recreated

• ❌ no other constructors can be written

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5. Question 5 – Calling one constructor from another

• ❌ two objects are created

• ❌ class name is used

• ❌ this must be last line

• ✔️ this must be the first line of the constructor

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6. Question 6 – The two setAge methods

• ❌ accessors

• ✔️ overloading

• ❌ overriding

• ✔️ mutators

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✅ SUMMARY TABLE

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