Calculating frequency of each word in a sentence in java
Try this
public class Main
{
public static void main(String[] args)
{
String text = "the quick brown fox jumps fox fox over the lazy dog brown";
String[] keys = text.split(" ");
String[] uniqueKeys;
int count = 0;
System.out.println(text);
uniqueKeys = getUniqueKeys(keys);
for(String key: uniqueKeys)
{
if(null == key)
{
break;
}
for(String s : keys)
{
if(key.equals(s))
{
count++;
}
}
System.out.println("Count of ["+key+"] is : "+count);
count=0;
}
}
private static String[] getUniqueKeys(String[] keys)
{
String[] uniqueKeys = new String[keys.length];
uniqueKeys[0] = keys[0];
int uniqueKeyIndex = 1;
boolean keyAlreadyExists = false;
for(int i=1; i<keys.length ; i++)
{
for(int j=0; j<=uniqueKeyIndex; j++)
{
if(keys[i].equals(uniqueKeys[j]))
{
keyAlreadyExists = true;
}
}
if(!keyAlreadyExists)
{
uniqueKeys[uniqueKeyIndex] = keys[i];
uniqueKeyIndex++;
}
keyAlreadyExists = false;
}
return uniqueKeys;
}
}
Output:
the quick brown fox jumps fox fox over the lazy dog brown
Count of [the] is : 2
Count of [quick] is : 1
Count of [brown] is : 2
Count of [fox] is : 3
Count of [jumps] is : 1
Count of [over] is : 1
Count of [lazy] is : 1
Count of [dog] is : 1
In Java 8, you can write this in two simple lines! In addition you can take advantage of parallel computing.
Here's the most beautiful way to do this:
Stream<String> stream = Stream.of(text.toLowerCase().split("\\W+")).parallel();
Map<String, Long> wordFreq = stream
.collect(Collectors.groupingBy(String::toString,Collectors.counting()));
import java.util.*;
public class WordCounter {
public static void main(String[] args) {
String s = "this is a this is this a this yes this is a this what it may be i do not care about this";
String a[] = s.split(" ");
Map<String, Integer> words = new HashMap<>();
for (String str : a) {
if (words.containsKey(str)) {
words.put(str, 1 + words.get(str));
} else {
words.put(str, 1);
}
}
System.out.println(words);
}
}
Output: {a=3, be=1, may=1, yes=1, this=7, about=1, i=1, is=3, it=1, do=1, not=1, what=1, care=1}
Use a map with word as a key and count as value, somthing like this
Map<String, Integer> map = new HashMap<>();
for (String w : words) {
Integer n = map.get(w);
n = (n == null) ? 1 : ++n;
map.put(w, n);
}
if you are not allowed to use java.util then you can sort arr using some sorting algoritm and do this
String[] words = new String[arr.length];
int[] counts = new int[arr.length];
words[0] = words[0];
counts[0] = 1;
for (int i = 1, j = 0; i < arr.length; i++) {
if (words[j].equals(arr[i])) {
counts[j]++;
} else {
j++;
words[j] = arr[i];
counts[j] = 1;
}
}
An interesting solution with ConcurrentHashMap since Java 8
ConcurrentMap<String, Integer> m = new ConcurrentHashMap<>();
m.compute("x", (k, v) -> v == null ? 1 : v + 1);