setting the length of an array's string element to a variable in a for loop in javascript

Question

I have this code. and for some reason i get the error: Uncaught TypeError: Cannot read property 'length' of undefined. I can't seem to figure out why.

function findShort(s) {

  var c = s.split(' ');
  var l = c[0].length;
  var wordlength;

  for (var i = 1; c.length; i++) {
    console.log(c[i].length);

    wordlength = c[i].length;
    if (l < wordlength) {
      l = wordlength;

    }
  }
  return l;

}

console.log(findShort("hello dog cat 12 asdsad wuidhuiwqhd"));

the error is with the line wordlength = c[i].length;

When i console.log it, it shows the length of each string in the array. However, when i try to store that length it says it's undefined.

You have an infinite loop, since c.length doesn't change during the loop. So you keep going past the end of the array. — Barmar
– Barmar, Commented Sep 27, 2016 at 0:19
doh! i can't believe i didn't notice that. thank you so much — sourlemonaid
– sourlemonaid, Commented Sep 27, 2016 at 0:22
console.log(Math.min.apply(null, 'the quick brown fox jumped'.split(' ').map(w=>w.length))); // outputs "3" — 000
– 000, Commented Sep 27, 2016 at 0:23
whoa. way better solution. I will have to learn more about arrow functions and mapping. thank you! — sourlemonaid
– sourlemonaid, Commented Sep 27, 2016 at 0:24

redneb · Accepted Answer · 2016-09-27 00:34:45Z

3

You need to change this line

for ( var i = 1; c.length; i++ ) {

to

for ( var i = 1; i<c.length; i++ ) {

The second componenet of a for loop is a boolean condition that is checked for every round of the loop to determine if the loop should continue or not. By putting c.length, you are giving a constant value which will make the loop to either never run (if c.length is 0), or to run forever (if c.length not 0).

You should also be careful with the following line:

var l = c[0].length;

It might cause a problem too as it is not guaranteed that c will have at least one element.

edited Sep 27, 2016 at 0:34

answered Sep 27, 2016 at 0:18

redneb

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1 Comment

sourlemonaid Over a year ago

I am a moron. Didn't notice that and i poured over the code 100 times. thank you very much

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