Question

In Worked Example 10.1, add a default method default int [] values(int n) that yields an array of the first n values of the sequence.

Please use only the code provided below from the worked example and if possible provide screenshots using all the code provided and the test class provided:

Sequence.java

public interface Sequence

{

int next();

}

LastDigitDistribution.java

public class LastDigitDistribution
{
public void process(Sequence seq, int valuesToProcess) {   
  
for (int i = 1; i <= valuesToProcess; i++) {
int value = seq.next();
int lastDigit = value % 10; counters[lastDigit]++;
}
}
}

SquareSequence.java

public class SquareSequence implements Sequence
{
private int n;

public int next()
{
n++;
return n * n;
}
}

RandomSequence.java

public class RandomSequence implements Sequence {
  
public int next() {
  
return (int) (Integer.MAX_VALUE * Math.random());
}
}

SequenceDemo.java

public class SequenceDemo {
  
public static void main(String[] args) {
  
LastDigitDistribution dist1 = new LastDigitDistribution();
dist1.process(new SquareSequence(), 1000);
dist1.display();

System.out.println();

LastDigitDistribution dist2 = new LastDigitDistribution();
dist2.process(new RandomSequence(), 1000);
dist2.display();
}
}

Answer 1

Modified code is given below. Only the code in the interface will change. The question asks for a default method, it has been implemented in the interface shown below

public interface Sequence
{

   int next();
   default int [] values(int n){
       int[] v = new int[n];
       for(int i = 0; i < n; i++)
           v[i] = next();
       return v;
   }
}