print out string instead of references

Question

I'm trying to find the top k frequent word in an input string. However, in my test case, it's printing out [Ljava.lang.String;@38af3868 even I tried to use the toString methods. What do I need to do to print out the string output instead of references? I should see strings as {"a","b"} here instead of references.

public class TopKFrequentWords {
     public static void main(String[] args) {
               TopKFrequentWords s = new TopKFrequentWords();
               String [] e1 =  {"a", "b", "c", "a", "b"};
               String[] res = s.topKFrequent(e1,2);
               System.out.print(res.toString()); //is not printing out strings
           }
        
            public String[] topKFrequent(String[] combo, int k) {
                if (combo.length == 0) {
                    return new String[0];
                }
                Map<String, Integer> freqMap = getFreqMap(combo);
                PriorityQueue<Map.Entry<String, Integer>> minHeap = new PriorityQueue<>(k,
                        new Comparator<Map.Entry<String, Integer>>() {
                    public int compare(Map.Entry<String, Integer> e1, Map.Entry<String, Integer> e2) {
                        //compareTo compares map e1's fre with e2's freq
                        return e1.getValue().compareTo(e2.getValue());
                    }
                });
                // .entry set() returns a collection view of the mappings contained in the map
                for (Map.Entry<String, Integer> entry: freqMap.entrySet()) {
                    if (minHeap.size() < k) {
                        minHeap.offer(entry);
                    } else if (entry.getValue() > minHeap.peek().getValue()) {
                        minHeap.poll();
                        minHeap.offer(entry);
                    }
                }
                return freqArray(minHeap);
            }
        
            private Map<String, Integer> getFreqMap(String[] combo) {
                Map<String, Integer> freqMap = new HashMap<>();
                //for s in combo; for i = 0; i< combo.length(), i++
                for (String s: combo) {
                    Integer freq = freqMap.get(s);
                    if (freq == null) {
                        freqMap.put(s,1);
                    } else {
                        freqMap.put(s, freq + 1);
                    }
                }
                return freqMap;
            }
        
            private String[] freqArray(PriorityQueue<Map.Entry<String, Integer>> minHeap) {
                String[] res = new String[minHeap.size()];
                for (int i = 0; i < minHeap.size(); i++) {
                    res[i] = minHeap.poll().getKey();
                }
                return res;
            }
        
          
        
        }

Answer 1

See: What's the simplest way to print a Java array?

System.out.println(Arrays.toString(array));

One can also use Java Streams:

Arrays.stream(arr).forEach(e->System.out.print(e));