[php] php Replacing multiple spaces with a single space

I'm trying to replace multiple spaces with a single space. When I use ereg_replace, I get an error about it being deprecated.

ereg_replace("[ \t\n\r]+", " ", $string);

Is there an identical replacement for it. I need to replace multiple " " white spaces and multiple nbsp white spaces with a single white space.

preg_replace("/[[:blank:]]+/"," ",$input)

$output = preg_replace('/\s+/', ' ',$input);

\s is shorthand for [ \t\n\r]. Multiple spaces will be replaced with single space.