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X1042: Complete CompareLastNames

Use the Person class below. Note that this class does NOT implement the Comparable interface.

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  public class Person {
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    // ...
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    public Person (String f, String l) { ... }
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    public int compareTo(Person o) { ... }
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    public String getFirst() { ... }
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    public String getLast() { ... }
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    @Override
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    public String toString() { return getLast()+", "+getFirst(); }
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  }

For this problem you must complete the following class.

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public class CompareLastNames implements Comparator<Person>
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{
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  public int compare(Person o1, Person o2) {
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    // your code goes here
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  }
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}

Complete the compare() method in the class above as described below. The method takes as a parameter two objects of type Person named o1 and o2.

  • If o1 and o2 are both null, return 0.
  • If o1 is null, return -1.
  • If o2 is null, return 1.
  • If the last name in o1 is less than the last name in o2, return -1.
  • If the last name in o1 is greater than the last name in o2, return 1.
  • If the last name in o1 is equal to the last name in o2, return 0.

Your Answer:

​x
 
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int compare(Person o1, Person o2)
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{
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}
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​
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