Quiz Inheritance Corrections

Example 1:

Consider the following class definitions.

public class A{

private int a1;

public void methodA() {

methodB();          // Statement I

}

}

public class B extends A {

public void methodB() {

methodA();          // Statement II

a1 = 0;             // Statement III

}

}

Which of the labeled statements in the methods shown above will cause a compile-time error?

II and III

II and III

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0 (with margin: 0)

Between 0 and 0

+/-

0

III only

III only

exact_answernone9197

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Between 0 and 0

+/-

0

I and II

I and II

exact_answernone8885

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Between 0 and 0

+/-

0

I and III

 

EXPLANATION:

I think a1 is declared as a private int in class A, so when class B extends A, it does not need to re-assign it to 0. I'm actually  not sure if this is the real reason, but that's what I'm going with for now. When it does this, it causes a compile-time error. methodB() will also cause this error because it is not defined.

 

I and III

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Between 0 and 0

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100

 Example 2:

true_false_question 26865425

<p> A subclass of an abstract class <strong>must always</strong> implement every defined abstract method.</p>

A subclass of an abstract class must always implement every defined abstract method.

True

exact_answernone238

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0

 

False

 EXPLANATION:

If the subclass is also an abstract class, it does not need to implement the abstract methods.