[рони]

AlexKotov,

var wordsContains = function(str, sub) {
   var separator = '[а-яёa-z]';
   var pattern = separator + '*' + sub + separator + '*';
   var reg = new RegExp(pattern, 'gi');
   var arr = str.replace(reg, '')
   reg = new RegExp(separator+ '+', 'gi');
   arr = arr.match(reg)||[]
   return arr

 }
 alert(wordsContains('Привет! Hello!hello!olo!world  qwerty', 'o'));