使用通配符搜索数组键

Say I have the following array:

$arr = array(
   "number2"=>"valid",
   "number13"=>"valid"
);

and I need to find if there is a key that exists with number*.

For $arr, this would be true. For the following array:

$arr2 = array(
   "key"=>"foo",
   "key2"=>"foo2"
);

this would return false.

This one assumes number needs to be followed by an actual number (edit: or nothing at all), adjust the regular expression as necessary. For example, anything starting with 'number', you could use /^number/.

if(count(preg_grep('/^number[\d]*/', array_keys($arr))) > 0)
{
   return true;
}
else
{
   return false;
}

Use regular expression.

foreach ($arr as $key => $value) {
  // NOTE: check for the right format of the regular expression 
  if (preg_match("/^number([0-9]*)$", $key)) {
    echo "A match was found.";
  } else {
    echo "A match was not found.";
  }
}

Here is a simple function which will do what you want:

function preg_grep_key($pattern, $input) {
    return preg_grep($pattern, array_keys($input));
}

// ----- Usage -----

$arr = array(
   "number2"=>"valid",
   "number13"=>"valid"
);


if (count(preg_grep_key('/^number/', $arr)) === 0) {
    // Nope
} else {
    // Yep
}