Count a substring within a string with JS (substr count equivalent)

[Bigzed]

Hey Guys,
I'm used to PHP, so I know substr_count(). How do I do that with JS: counting how many occurrences of a substring are within one string.
e.g. there's two substrings 'p' in the string 'apple'.

Thanks!
Bigzed.

[Bigzed]

got it:

<script type="text/javascript">
var _s = '25fdjkkjlafjkl25alksdfjaafdjk25sl'; // haystack
var _m = '25'; // needle
var _c = 0;
for (var i=0;i<_s.length;i++) {
if (_m == _s.substr(i,_m.length))
_c++;
}
alert(_c);
</script>