Longest Word in Every Language

Published on 31 October 2020 (Updated: 31 October 2020)

Longest Word in Every Language

Welcome to the Longest Word page! Here, you’ll find a description of the project as well as a list of sample programs written in various languages.


Given a string, this program should break it up into words and determine the length of the longest word. In this case, a word is defined as anything surrounded by whitespace. For simplicity, we’ll restrict whitespace to the following four special characters:

For example, if we had a string, “How now brown cow”, we can figure out which word is the longest by breaking up the string into words. In this case, this string has the following four words:

In this case, “brown” is clearly the longest word, so we’ll return 5 as a result.


To satisfy the requirements, a program must accept a string on the command line and return the length of the longest word in the string:

$ ./longest-word-in-string.lang "Google do a barrel roll"
$ 6

In this case, we have a string with 5 words. It appears that there are two words that share the largest number of characters: Google and barrel. Naturally, we don’t care to decide between the two words. Instead, we return the length of them both: 6.


The following table contains various test cases that you can use to verify the correctness of your solution:

Description Input Output
No Input   “Usage: please provide a string”
Empty Input ”” “Usage: please provide a string”
Sample Input: Many Words “May the force be with you” 5
Sample Input: Single Word “Floccinaucinihilipilification” 29
Sample Input: Multiline “Hi,\nMy name is Paul!” 5

As always, these tests will be run against any code submitted to the repo via [Glotter][glotter-github].