PHP explode return different results [duplicate]

I have a string from front end application json. Need to call explode(‘ ‘, $string) on it and make some logic above the result. The string looks like “27 609,66 CZK”. But it seems like there are not spaces in the string and explode return whole string as is. I also tried to use non beaking space sign as separator. But no success. I made simple test on it which looks like:

$a = explode(" ", "27 609,66 CZK");  // This is the application string
$b = explode(" ", "27 609,66 CZK");  // This is written on keyboard

var_dump($a);
var_dump($b);

The result looks like

array (size=1)
  0 => string '27 609,66 CZK' (length=15)

array (size=3)
  0 => string '27' (length=2)
  1 => string '609,66' (length=6)
  2 => string 'CZK' (length=3)

Can somebody tell me plaese what could be the problem?