javascript - Match words in a string and make them lowercase -

i have example string:

var string = 'this süper nice sentence, right?'; 

the result has be:

this, is, süper, nice, sentence 

requirements:

1. 5 words max,
2. words contain @ least 2 characters
3. comma separated
4. takes care of special characters such ü this not happening
5. all in lowercase this not happening

this current script: (you can test in jsfiddle)

var string = 'this süper nice sentence, right?'; var words; words = string.replace(/[^a-za-z\s]/g,function(str){return '';}); words = words.match(/\w{2,}/g);  if(words != null) {     //5 words maximum     words = words.slice(0,5);     if(words.length) {         console.log(words.join(', ')); //should print: this, is, süper, nice, sentence     } } 

what best way convert matched words lowercase before join?

the answer tolowercase(), think best place run right @ end rather beginning (fewer items operate on):

if(words != null) {     //5 words maximum     words = words.slice(0,5);     if(words.length) {         console.log(words.join(', ').tolowercase()); //here     } } 

tolowercase() is, far know, unicode-friendly. regex stripping not a-z,a-z.

asker found link helpful resolving regex issue: regular expression match non-english characters?