validate time GMT offset and striping with regex ?

Question

// create a string
$string = '+7';

// try to match the beginning of the string
if(preg_match("{-15 to +12}", $string))
    {
    // if it matches we echo this line
    return {strip all the + sign}
    echo 'its a valid gmt time';
    }
else
    {
    echo 'not valid gmt time';
    }

Question:

1. please see the first {} on preg_match, is how can we do that ? im new on regex and i just dont know where to start

2. on the second {} can we somehow strip the + sign by useing regex ?

3. is the gmt range is right ? -14 to +12 ( well thats what i see on http://www.php.net/manual/en/timezones.others.php )

Thanks

Answer 1

Here ya go:

1. //match 0-15 with a +,- in front.

   if(preg_match("/(+|-)([0-9]|1[1-5])/", $string)){
         //match process here 
   }
   

That would match your -15,+12 I would imagine.

1. To strip out all the {+} signs.

   //take out + and replace with + $newString = str_replace(array("+"),"", $oldString);

Answer 2

The regexp could be:

/\+?[0-9]|\+?1[0-2]|\-[1-9]|\-1[0-5]/

This would match 0..12, +0..+12, -1..-15
If the + sign is required, use the RegExp without the ?.

then just do a str_replace on the number:

$number = str_relace('+', '', $number);

Answer 3

I would do :

preg_match("/^([+-]\d+)/", $string, $m);
if(isset($m[1]) && $m[1] > -16 && $m[1] < 13) {
    echo 'its a valid gmt time';
} else {
    echo 'not valid gmt time';
}

Answer 4

function validGMT($input)
{
    $gmt = '/^(?:\+?(?:[0]?[0-9]|[1][0-2])|-(?:[0][0-9]|[1][0-4]))$/';
    if ( preg_match( $gmt, $input ) )
    {
        return true;
    }
    else
    {
        return false;
    }       
}

edit*

ive just notice that if you are at php5.2. do this

$val='-2';
$options['options']['min_range'] = -14;
$options['options']['max_range'] = 12; 
$var1 = filter_var($val, FILTER_VALIDATE_INT,$options);
var_dump($var1);   

Answer 5

$string = '+7';
if (in_array($string, range(-15, 12))) {
    echo 'its a valid gmt time';
} else {
    echo 'not valid gmt time';
}