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Java

Posted by Derek Derek
Derek Derek
8,744 Points

Java WordCount

Hello, I am trying to write a WordCount program using java Hashmap. I think I am almost there, but I keep getting an error in my hashmap.get(key) method.. I really appreciate your help!

import java.util.HashMap;


public class MapReduce {
    public static void main(String[] args) {
        count("to be or not to be");

    }

    public static void count(String sentence) {
        String[] words = sentence.split("(?=[,.])|\\s+");
        HashMap<String, Integer> hashmap = new HashMap<String, Integer>();

        for (String word : words) {
            if (hashmap.containsKey(word)) {
                hashmap.get(word) += 1;
            } else {
                hashmap.put(word, 1);
            }
        }
        System.out.println(hashmap.entrySet());
    }
}

Error message:

/Users/HyunJaeCho/Desktop/MapReduce.java:16: error: unexpected type hashmap.get(word) += 1; ^ required: variable found: value 1 error [Finished in 0.7s with exit code 1]

2 Answers

Tatenda Mushayakarara
Tatenda Mushayakarara
2,447 Points
Tatenda Mushayakarara
Tatenda Mushayakarara
2,447 Points 
public static void count(String sentence) {
        String[] words = sentence.split("(?=[,.])|\\s+");
        HashMap<String, Integer> hashmap = new HashMap<>();

        for (String word : words) {
            if (hashmap.containsKey(word)) {
                hashmap.get(word + 1);
            } else {
                hashmap.put(word, 1);
            }

you should put the "+ 1 "inside the parenthesis. I hope it is clear. i cant find my words

Derek Derek
Derek Derek
8,744 Points

Hi, Tatenda, thank you for your help.

I don't think it is right though.. I am getting wrong results.. Also, it is not clear to me how you can add 1 to word which is a String..

Tatenda Mushayakarara
Tatenda Mushayakarara
2,447 Points
Tatenda Mushayakarara
Tatenda Mushayakarara
2,447 Points

hi.. I tried that piece of code over eclipse and it ran. Can you ask the question again this time with a link to show which challenge it was and I will take a look into it. Thanks!