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Java

Paul Lemky
PLUS
Paul Lemky
Courses Plus Student 15,502 Points

Position of Code treetsByAuthor.put(treet.getAuthor(),authoredTreets);

Shouldn't this snippet be outside of the if (authoredTreets==null) statement and authoredTreets.add(treet); ?

So the whole thing should look like below:

Map<String,List<Treet>> treetsByAuthor = new HashMap<String,List<Treet>>();

for (Treet treet : treets){
 List<Treet> authoredTreets = treetsByAuthor.get(treet.getAuthor());
 if (authoredTreets==null){
  authoredTreets=new ArrayList<Treet>();
 }
 authoredTreets.add(treet);
 treetsByAuthor.put(treet.getAuthor(),authoredTreets);
}
System.out.printf("Treets by Author: %s",treetsByAuthor);