如果你不知道数字的格式?Int或float，然后使用这个:

$string = '$125.22';

$string2 = '$125';

preg_match_all('/(\d+.?\d+)/',$string,$matches); // $matches[1] = 125.22

preg_match_all('/(\d+.?\d+)/',$string2,$matches); // $matches[1] = 125

$value = '25%';

Or

$value = '25.025$';

Or

$value = 'I am numeric 25';
$onlyNumeric = filter_var($value, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION);

这将只返回数值

preg_replace('/[^0-9]/', '', $string);

这应该做得更好!

这个函数也将处理浮点数

$str = "Doughnuts, 4; doughnuts holes, 0.08; glue, 3.4";
$str = preg_replace('/[^0-9\.]/','-', $str);
$str = preg_replace('/(\-+)(\.\.+)/','-', $str);
$str = trim($str, '-');
$arr = explode('-', $str);

你可以使用preg_match:

$s = "In My Cart : 11 items";
preg_match("|\d+|", $s, $m);
var_dump($m);

对于浮点数，

preg_match_all('!\d+\.?\d+!', $string ,$match);

谢谢你指出错误。@mickmackusa