String, check and remove duplicate characters

[TheDigglerUK]

Hi,

I am trying to remove duplicate commas in a string leaving just one with the following code. but it removes all duplicate characters, how can i do it just to remove the commas?

$str = 'aabb,,ccaaaaadd,,,ee';
echo preg_replace('{(.)\1+}','$1',$str);

Thanks

Jules

[NogDog]

echo preg_replace('/,{2,}/', ',', $str);

[sela]

echo preg_replace('/,+/', ',', $str);