如何使用preg_match获取第一个数字字符？

I have phone number. If the first numeric character of a number is not 1 I need to add it. I can't find out how to do it with preg_match, or is there any other way?

$first_number = $number;
if(preg_match('something', $first_number, $result))
{
$first_number = '1'. $result[1];
}

There is not need to go for regex here. You can do:

if($first_number[0] != '1') {
    $first_number = '1'.$first_number;
}

But if the number can have leading spaces or a + sign you can do:

if(preg_match('/^(\D*)(\d)/',$first_number,$match))
    $first_number = $match[1].'1'.$match[2];
}

No need to use preg_match or preg_replace here, the simple solution below should work

if ($number[0] != 1)
{
  $number.= '1'. $number;
}

use

'/^([^1][0-9]+)$/'

It should do the trick!

The first non-numeric character isn't always at position 1 in the array, if I'm reading your question right.

$n="foo 415";
preg_match("/^[^0-9]*([0-9])/", $n, $matches);
print $matches[0]."
";'

returns 4.