I've defines a function printWordsOccurence(String str). it's job to print How many times is each word repeated in this text :

Text: I am happy. I am a doctor. I like chocolate.

the expected results :

1. [3] I
2. [2] am
3. [1] happy.
4. [1] a
5. [1] doctor.
6. [1] like
7. [1] chocolate.

Here is my code :

 public static void printWordsOccurence(String str) {

    String[] words = str.split(" ");
    int counter = 0;

    for (int i = 0; i < words.length; i  ) {
        for (int j = 0; j < words.length; j  ) {
            if (words[i].equals(words[j])) {
                counter  ;
            }
        }
        System.out.println(counter   " "   words[i]);
        counter=0;
    }
}

I can't prevent strings from repeating. Any suggestions or hint would be very helpful

CodePudding user response：

What you need to do is to not process words you have already seen. So when the outer loop sees a familiar one it needs to skip it.

The easiest way do do this would be to use a set or a map. But there is another alternative using most of your existing code.

• simply replace the word when it is encountered with some string.
• then if that string is encountered again by the outer loop, ignore it.

public static void printWordsOccurence(String str) {
    
    String[] words = str.split(" ");
    // the marker which replaces the word when found.
    String seen = "#";

    for (int i = 0; i < words.length; i  ) {
        
        // if the word equals the marker, continue continue on
        // to the next word in this loop
        if (words[i].equals(seen)) {
            continue;
        }

        int counter = 0;

        // save the word since it may change when found
        String find = words[i];

        for (int j = 0; j < words.length; j  ) {
            if (find.equals(words[j])) {
                // replace the word with the substitute
                words[j] = seen;
                counter  ;
            }
        }
        
        System.out.println(counter   " "   find);
    }
}

prints

3 I
2 am
1 happy.
1 a
1 doctor.
1 like
1 chocolate.

You may want to modify the words to eliminate any lingering punctuation.

CodePudding user response：

You are printing the message within the outer loop and it will get executed for each of the words! Please try to use Map. Here I don't use the stream. Just used Java 7 way. `

public static void printWordsOccurence(String str) {

        String[] words = str.split(" ");

        Map<String, Integer> res = new LinkedHashMap<>();

        for (String w : words) {
            if (res.containsKey(w)) {
                res.put(w, res.get(w)   1);
            } else {
                res.put(w, 1);
            }
        }

        for (String w: res.keySet()) {
            System.out.println("["   res.get(w)   "]"   w);
        }
    }

`

CodePudding user response：

private static void printWordOccurance(String sentence) {
    Map<String, Integer> countMap = new HashMap<>();
    Arrays.stream(sentence.split("\\s ")).forEach(word -> countMap.compute(word, (k, v) -> v == null ? 1 : v   1));
        
    System.out.println(countMap);
}

CodePudding user response：

    using [https://docs.oracle.com/javase/8/docs/api/java/util/Map.html][1]

        String str= "I am happy. I am a doctor. I like chocolate.";
        str= str.replace(".", "");

        String[] words = str.split(" ");
        Map<String, Integer> counter = new HashMap<>();

        for (String w: words) {
            if(counter.containsKey(w)){
                counter.replace(w, counter.get(w) 1);
            }else{
                counter.put(w,1);
            }
        }
        System.out.println(counter.toString());

CodePudding user response：

Try this.

public static void printWordsOccurence(String str) {
    Arrays.stream(str.split("[\\s.] "))
        .collect(Collectors.groupingBy(Function.identity(),
            LinkedHashMap::new, Collectors.counting()))
        .entrySet().forEach(e ->
            System.out.println("["   e.getValue()   "] "   e.getKey()));
}

public static void main(String[] args) {
    String str = "I am happy. I am a doctor. I like chocolate.";
    printWordsOccurence(str);
}

output:

[3] I
[2] am
[1] happy
[1] a
[1] doctor
[1] like
[1] chocolate

Or

public static void printWordsOccurence(String str) {
    Map<String, Integer> counter = new LinkedHashMap<>();
    for (String word : str.split("[\\s.] "))
        counter.merge(word, 1, Integer::sum);
    for (Entry<String, Integer> e : counter.entrySet())
        System.out.println("["   e.getValue()   "] "   e.getKey());
}