Imagine there is a class named Word which extends String. A Word is a specific sort

of String, which includes only alphabetical characters and has methods such as

getDefinition, getPartOfSpeech, and conjugate. Is there a problem with the following

method which, is meant to Override String's compareTo method?

@Override

public int compareTo$($Word w$)$

$\{$

String s$1=$ this.toString$()$;

String s$2=$ w$.$toString$()$;

return s$1.$compareTo$($s$2)$;

$\}$

Yes, there's a problem. The method should take a String as input.

No problem. It is a valid compareTo

Yes, there's a problem. The method should return a boolean.

Yes, there's a problem. The method should cast this and w to String rather than

relying on toString methods.

I have a method:

public double importantDataChange$($double $x,$ double $y)$

And I need to make it so that while one thread is using the importantDataChange

method, no other threads can interact with the containing object. Which of the

following changes to the method header makes it so$?$

public synchronized double importantDataChange$($double $x,$ double $y)$

public double synchronized importantDataChange$($double $x,$ double $y)$

public double importantDataChange$($double $x,$ double $y)$ implements

synchronized

None of the above because synchronized only acquires the lock for the method,

not the whole object.