JavaScript: Accept a list of words and returns the longest

JavaScript Function: Exercise-25 with Solution

Write a JavaScript function that accept a list of country names as input and returns the longest country name as output

Sample function : Longest_Country_Name(["Australia", "Germany", "United States of America"])
Expected output : "United States of America"

Pictorial Presentation:

JavaScript: Accept a list of words and returns the longest

Sample Solution: -

HTML Code:

<!DOCTYPE html>
  <meta charset="utf-8">
  <title>Find longest word</title>


JavaScript Code:

function Longest_Country_Name(country_name)
  return country_name.reduce(function(lname, country) 
    return lname.length > country.length ? lname : country;
console.log(Longest_Country_Name(["Australia", "Germany", "United States of America"]));


United States of America


Flowchart: JavaScript function: Accept a list of words and returns the longest

Live Demo:

See the Pen JavaScript - Bubble Sort algorithm-function-ex- 24 by w3resource (@w3resource) on CodePen.

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Next: Write a JavaScript function to find longest substring in a given a string without repeating characters.

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JavaScript: Tips of the Day

How to check whether a string contains a substring in JavaScript?

ECMAScript 6 introduced String.prototype.includes:

const string = "foo";
const substring = "oo";


includes doesn't have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns -1 when a substring cannot be found:

var string = "foo";
var substring = "oo";

console.log(string.indexOf(substring) !== -1);

Ref: https://bit.ly/3fFFgZv