Java Program to count words in a sentence using lambda expression

Java Lambda Program: Exercise-13 with Solution

Write a Java program to implement a lambda expression to count words in a sentence.

Sample Solution:

Java Code:

public class Main {
  public static void main(String[] args) {
    String text = "Java lambda expression.";
    System.out.println("Original string: " + text);
    WordCounter wordCounter = s -> s.split("\\s+").length;
    int ctr = wordCounter.countWords(text);
    System.out.println("Word count: " + ctr);
    text = "The quick brown fox jumps over the lazy dog.";
    System.out.println("\nOriginal string: " + text);
    wordCounter = s -> s.split("\\s+").length;
    ctr = wordCounter.countWords(text);
    System.out.println("Word count: " + ctr);
  }
}

@FunctionalInterface
interface WordCounter {
  int countWords(String text);
}

Sample Output:

Original string: Java lambda expression.
Word count: 3

Original string: The quick brown fox jumps over the lazy dog.
Word count: 9

Explanation:

In the above code the wordCounter variable is assigned a lambda expression that splits the input string by whitespace (\\s+) and counts the number of resulting substrings using the length method. The countWords method of the wordCounter instance is then called with the text string. The result is stored in the "ctr" variable. Finally, the word count is printed to the console.

Flowchart:

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