# freeCodeCamp Algorithm Challenge Guide: Find the Longest Word in a String

freeCodeCamp Algorithm Challenge Guide: Find the Longest Word in a String
0

#1

Remember to use `Read-Search-Ask` if you get stuck. Try to pair program and write your own code

### Problem Explanation:

You have to go through each word and figure out which one is the longest and return not the word, but how many characters it has.

## Hint: 1

You should split the string into an array of words.

try to solve the problem now

## Hint: 2

You will need to figure out a way to keep track of the greatest current length.

try to solve the problem now

## Hint: 3

Remember how to get the length of elements on the array? `Array[index].length`.

try to solve the problem now

## Basic Code Solution:

``````function findLongestWord(str) {
var words = str.split(' ');
var maxLength = 0;

for (var i = 0; i < words.length; i++) {
if (words[i].length > maxLength) {
maxLength = words[i].length;
}
}

return maxLength;
}
``````

### Code Explanation:

Take the string and convert it into an array of words. Declare a variable to keep track of the maximum length and loop from 0 to the length of the array of words.

Then check for the longest word by comparing the current word to the previous one and storing the new longest word. At the end of the loop just return the number value of the variable maxLength.

## Intermediate Code Solution:

Using `.reduce()`

``````function findLongestWord(s) {
return s.split(' ')
.reduce(function(x, y) {
return Math.max(x, y.length)
}, 0);
}
``````

### Code Explanation:

For more information on `reduce` click here.

In case you’re wondering about that `0` after the callback function, it is used to give an initial value to the `x`, so that `Math.max` will know where to start.

Using recursiveness

``````function findLongestWord(str) {

//split the string into individual words
//(important!!, you'll see why later)
str = str.split(" ");

//str only has 1 element left that is the longest element,
//return the length of that element
if(str.length == 1){
return str[0].length;
}

//if the first element's length is greater than the second element's (or equal)
//remove the second element and recursively call the function)
if(str[0].length >= str[1].length){
str.splice(1,1);
return findLongestWord(str.join(" "));
}

//if the second element's length is greater thant the first element's start
//call the function past the first element
if(str[0].length <= str[1].length){
// from the first element to the last element inclusive.
return findLongestWord(str.slice(1,str.length).join(" "));
}
}
``````

### Code Explanation:

The first line splits the string into individual words. Then we check if `str` only has 1 element left then that is the longest element and we return it. If the first element’s length is greater than the second element’s (or equal), we remove the second element and recursively call the function `findLongestWord`. However, if the second element’s length is greater thant the first element’s start, then we call the function past the first element.

## NOTES FOR CONTRIBUTIONS:

• DO NOT add solutions that are similar to any existing solutions. If you think it is similar but better, then try to merge (or replace) the existing similar solution.
• Categorize the solution in one of the following categories — Basic, Intermediate and Advanced.

See `Wiki Challenge Solution Template` for reference.

#2

#3

#5

The `JS Math Max` link in the intermediate function explanations returns-

{“errors”:[“The requested URL or resource could not be found.”],“error_type”:“not_found”}

It might just be to MDN anyway, but I didn’t know if it was a special FCC article.

#6

First ,when i use split(), I found str1 is a list, so , I just think why not get a list which contain every word’s length.
So I get a list of number, next problem is found the max number of the list, just google js max, so i get the solution.
I have compare my solution with official, my solution is not perfect ,but it’s a another way.
I feel happy with that.

`function findLongestWord(str) {
var str1 = str.split(" ");
var list = [];
for (i=0;i<str1.length;i++) {
list.push(str1[i].length) ;
}
return Math.max.apply(null ,list);
}

findLongestWord(“The quick brown fox jumped over the lazy dog”);`

#8
``````function findLongestWord(str) {
``````

return str.split(’ ').map(function(val){
return val.length;
}).sort(function(a, b){
return b - a;
})[0];

}

findLongestWord(“The quick brown fox jumped over the lazy dog”);

#9

This is my solution:

``````function findLongestWord(str) {

var arr = str.split(" ");//split sentence to an array
var longestWord = arr[0];//assume longest word is the first word of an array
for (var i=0; i< arr.length; i++){ //iterate through array of words

if(arr[i].length > longestWord.length){
//compare other words of an array if they are longer than the first one
longestWord = arr[i];
}
}
return longestWord.length;//return length of the longest word

}
//test
findLongestWord("What if we try a super-long word such as otorhinolaryngology");``````

#10

Here is my take on a solution.

``````function findLongestWord(str) {
return Math.max.apply(Math, str.split(' ').map(val = val => val.length));}
``````

#11

Hi! I wanted to contribute with my solution

``````function findLongestWord(str) {

// Split the string into an array
var array = str.split(" ");

// Then sort the array by its elements length, from longest to shortest
array.sort(function(a,b) {
return b.length - a.length;
});

// Since the first element of the array will be the longest, then return the length of the first element
return array[0].length;
}

findLongestWord("The quick brown fox jumped over the lazy dog");``````

#12

Hi , i did it w/ sort function;

``````function findLongestWord(str) {
var abc = str.split(" ");
var newStr = [];
for (var i = 0; i < abc.length; i++) {

newStr.push(abc[i].length);
}
}

findLongestWord("The quick brown fox jumped over the lazy dog");

``````

#13

Very short code; how you managed to simply write var longestWord in a such way in if condition ; Appreciate Really!! your logic;

``````      function findLongestWord(str) {

var arr = str.split(" ");//split sentence to an array
var longestWord = arr[0];//assume longest word is the first word of an array
for (var i=0; i< arr.length; i++){ //iterate through array of words

if(arr[i].length > longestWord.length){
//compare other words of an array if they are longer than the first one
console.log(longestWord = arr[i]);
}
}
return //console.log(longestWord.length);//return length of the longest word

}
//test
findLongestWord("What if we try a super-long word such as otorhinolaryngology");
``````

`
examining your code, where I have written console log in gives two strings, while should give just a lonestWord; Why could you explain me plz

#14

What is the advantage of the Advanced/ Intermediate Code over the Basic?

#15

Hi there! This is my solution.

``````function findLongestWord(str) {
return str.split(" ").sort(function(a,b){
return b.length - a.length;
})[0].length;
}

findLongestWord("The quick brown fox jumped over the lazy dog");
``````

#16

Here is my take:slight_smile:

function findLongestWord(str) {
// Split the string into an array
var array = str.split(" ");
var lengths = array.map(function(word){
return word.length
})
var q = Math.max.apply(null, lengths);

return q

}`

#17

I really like the solutions using .reduce but I was wondering whether it is noticeably faster than the Basic Code Solution.

#18

function findLongestWord(str) {

var word = str.split(’ ');
var x = word[0].length;

for(i=0; i<word.length; i++){
if(word[i].length>x){
x = word[i].length;
}
}

return x;
}

findLongestWord(“The quick brown fox jumped over the lazy dog”);

#19

My solution here i used the .toLowerCase() so when sorted, it would not put the capital string first but any comments on my solution would help thanks.

function findLongestWord(str) {
var strArry=[];

strArry=str.toLowerCase().split(’ ');
strArry.sort(function(a,b){
return b.length-a.length;
});

return strArry[0].length;
}

findLongestWord(“What if we try a super-long word such as otorhinolaryngology”);

#20

I managed to reach the basic solution, and looking at the hints am trying to do the advanced solution, but am encountering a “Type Error: str.splice is not a function” error message that for the life of me I can’t figure out. Can anyone explain my mistake? Code is below, but I also had an question about the intermediate solution:

function findLongestWord(str) {

if (!str.isArray) {
str.split(" ");}

if (str.length == 1) {
return str[0];
}

if (str[0].length >= str[1].length) {
str.splice(1,1);
return findLongestWord(str);
}

if (str[0].length <= str[1].length) {
str.splice(0,1);
return findLongestWord(str);
}

}
findLongestWord(“The quick brown fox jumped over the lazy dog”);

Regarding the intermediate solution, can someone please explain the logic behind function(x, y) {
return Math.max(x, y.length)
}

Thanks

#21

Hi @Alais29,

I did the exact same thing .

#22

Why doesn’t this work?

``````var array = [];
function findLongestWord(str) {
var newArray = str.split(" ");

for (i = 0; i < newArray.length; i++) {
var newLength = newArray[i].length;
array = array.concat(newLength);

}
return array.reduce(function(previousValue, currentValue){
return Math.max(previousValue,currentValue);
});

}

findLongestWord("May the force be with you");``````