正则表达式检查以空格和总长度开头的字符串10 PHP

Question

I wrote PHP code to check the string with regular expression. Every string should start with white space and total length should be exactly 10.

$str = ' 123456789';
if(preg_match('/^([ 0-9]){10}+$/', $str)){
      echo 'true';
}
    echo 'false';

I have expected the following results when I change the $str variable. But using the above regular expression, I only get the first one right.

$str = ' 1234567890'; //true
$str = '1234567890'; // false 

Answer 1

If you truly mean white space then use \s as your white space because it grabs tabs as well. Also, It looks like you only want digits. If so use:

'/^\s\d{9}$/'

If not then use:

'/^\s.{9}$/'