How does this code know to return the length of the longest word in the string?

Question

This is my code:

function findLongestWord(str) {
    var arr = str.split(" ");
    var p = 0;
    for (i = 0; i < arr.length; i++) {
        if (arr[i].length > p){
            p = arr[i].length;
        }
    }
    return p;
}

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

I know it works, but I am unsure why it is able to pick out only the longest word of the string. I understand that the sting gets split into an array, and the for loop checks the length of each string in the array, but how does p=arr[i].length ALWAYS pick the longest one to return?

Answer 1

var arr = str.split(" ");

splits the string into an array of words.

P holds the maximum length found so far.

We iterate though the array of words and if a word is longer then p we assign it's length to p

Answer 2

At the begin p is equal to 0

for (i = 0; i < arr.length; i++) { //loop all words in array

if (arr[i].length > p){

only if p (the length of previous word) is longer than current

p = arr[i].length; //I update p with the current length (not always, but according to if statement)

So at end of loop p is equal to the length of longest word.

Answer 3

Well It's pretty easy : First you take the length of the first word (arr[0].length) and store the value in p.

Then you take the second one which is arr[1].length and compare it with the length of the first one which is stored in p. If the second word is bigger than the first (arr[1] > p) then p becomes array[1], etc.