Javascript Regex to select every non-alphanumeric character AND whitespace?

Question

I'm new to JS, tried using -

/[0-9a-z]+$/gi
/[^0-9a-z]+$/gi

neither worked. Can anyone tell me where I am going wrong?

The second one looks fine. Can you show us an example of how it's "not working"? — Cameron
– Cameron, Commented Aug 31, 2012 at 15:06
What do you mean by "neither worked"? 1. what where you trying to do? 2. what was the expected result ? 3. and most importantly: what happened instead? — Philipp
– Philipp, Commented Aug 31, 2012 at 15:08
try /\W{0,}/g, and try starting to accept some answers people give you. — KooiInc
– KooiInc, Commented Aug 31, 2012 at 15:09
I'm trying to find longest word in a string. A word qualifies as a group of letters and numbers, without any spaces in between. If I use ' ' instead of the regex, I get a fine solution. Here's the JSFiddle — Namanyay Goel
– Namanyay Goel, Commented Aug 31, 2012 at 15:11

raina77ow · Accepted Answer · 2012-08-31 15:43:20Z

1

Replace

var sentence_split = arr.split(/[0-9a-z]+$/gi);

with

var sentence_split = arr.split(/[^0-9a-z]+/gi);

... if you prefer to go this way.

Explanation: the original regex was anchored (with $) to the end of the string, and splitted by words - and not symbols separating them.

Still, there's more than one way to do the things you do: I'd probably go just with:

var words = sentence.match(/(\w+)/g);

... capturing sequences of word-consisting symbols instead of splitting the phrase by something that separates them. Here's a Fiddle to play with.

UPDATE: And one last thing. I felt a bit... uneasy about wasting sort just to get max essentially. I don't know if you share these thoughts, still here's how I would update the searching code:

var longest;
words.forEach(function(e) {
  if (! longest || longest.length < e.length) {
    longest = e;
  }
});

It's forEach, because I'm a bit lazy and imagine having a luxury of NOT working with IE8-; still, it's quite easy to rewrite this into a regular for... array-walking routine.

Updated fiddle.

edited Aug 31, 2012 at 15:43

answered Aug 31, 2012 at 15:13

raina77ow

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4 Comments

Namanyay Goel Over a year ago

Works! Thanks! Could you explain why?

raina77ow Over a year ago

BTW, it can be useful to console.log the array as well (as I did in my example to illustrate what would be captured).

Namanyay Goel Over a year ago

I do use console.log regularly.. EDIT. Could you help me change the code to for...? I have no clue how to... Just a few hints would help.

raina77ow Over a year ago

@Namanyayg Check forEach documentation page at MDN. It'll be helpful both for understanding its usage and possible ways of replacing it. )

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