Find the Longest Word in a String in JavaScript

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

Introduction

Finding the longest word in a string is a common problem in programming. In JavaScript, this can be achieved by splitting the string into individual words and then finding the word with the maximum length. This guide will walk you through writing a JavaScript program to find the longest word in a given string.

Problem Statement

Create a JavaScript program that:

• Accepts a string.
• Identifies and returns the longest word in the string.

Example:

• Input: "The quick brown fox jumps over the lazy dog"

• Output: "jumps" with length 5

• Input: "JavaScript is an amazing programming language"

• Output: "programming" with length 11

Solution Steps

1. Read the Input String: Provide a string either by user input or as part of a method.
2. Split the String into Words: Use the split() method to break the string into an array of words.
3. Find the Longest Word: Iterate through the array to find the word with the maximum length.
4. Display the Result: Print the longest word and its length.

JavaScript Program

// JavaScript Program to Find the Longest Word in a String
// Author: https://www.javaguides.net/

function findLongestWord(str) {
    // Step 1: Split the string into words
    const words = str.split(' ');
    
    // Step 2: Find the longest word
    let longestWord = words.reduce((longest, currentWord) => {
        return currentWord.length > longest.length ? currentWord : longest;
    }, "");

    // Step 3: Display the result
    console.log(`The longest word is: "${longestWord}" with length ${longestWord.length}`);
}

// Example input
let inputString = "The quick brown fox jumps over the lazy dog";
findLongestWord(inputString);

Output Example

The longest word is: "jumps" with length 5

Explanation

Step 1: Split the String into Words

• The split() method is used to break the string into an array of words. Each word is separated by spaces in the string.

Step 2: Find the Longest Word

• The reduce() function iterates through the array of words and compares the length of each word with the longest word found so far. The word with the maximum length is stored in the longestWord variable.

Step 3: Display the Result

• The longest word and its length are printed to the console.

Output Example with Different Input

If you modify the input string to:

let inputString = "JavaScript is an amazing programming language";

The output will be:

The longest word is: "programming" with length 11

Conclusion

This JavaScript program demonstrates how to find the longest word in a string using the split() and reduce() methods. By leveraging JavaScript's array manipulation functions, the code is concise and easy to understand. This exercise is useful for learning how to manipulate strings and arrays in JavaScript, as well as solving text-related problems in an efficient manner.

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF