Check string format with regular expression

Question

I need to check a string that comes from an ajax post with php, in particulare the source is a text area with this format:

[minute]:[price]
[minute]:[price]
[minute]:[price]

Example:

10:20
12:22.23
20:30.1

And so on, the minutes is an integer and the price could be a float with 0 to 2 decimals(10, 10.0, 10.00 are fine), I'm only able to check them in a simple way: double explode( "\n" and ":") and is_number + float on sub-element, but it looks pretty inconvenient, could someone suggests me an expression to use with preg_match?

Now that is a good expression looks pretty inconvenient, Why not try something fist and ask us why it is not working? — Ed Heal
– Ed Heal, Commented Dec 25, 2013 at 19:07
Ehm...it's a shame, but I don't know almost nothing about regex :( — Razorphyn
– Razorphyn, Commented Dec 25, 2013 at 19:10
This worked for me: (\d)+:(\d)+(.(\d)+)* - Check out this website for testing your regex: debuggex.com/#cheatsheet - I have only just started learning regex so there might be a better one but it worked for your 3 examples. — Jessica
– Jessica, Commented Dec 25, 2013 at 19:11
@Jessica the string comes from a textarea and I don't know if the new line could influence the regex — Razorphyn
– Razorphyn, Commented Dec 25, 2013 at 19:14

Caio Oliveira · Accepted Answer · 2013-12-25 22:33:20Z

1

This is probably what you want:

$re = '/[\d]{1,2}\:[\d]{1,2}(?:\.[\d]{1,2})?/m';
$str = "12:22\n12:22.23\n12:22.23";

preg_match_all($re, $str, $matches); //This catch only correct values

echo "<pre>";
foreach($matches[0] as $value){
  $split = explode(":", $value);
  $minute = intval($split[0]);
  $price = floatval($split[1]);

  echo "minute -> " . $minute . " value -> " . $price . "\n";
}

The expression /[\d]{1,2}\:[\d]{1,2}(?:\.[\d]{1,2})?/m catch patterns like 12:12.12. See Regex101 example

preg_match_all($pattern, $subject, $matches) Perform a global regular expression match and put the matches into the $matches array.

intval($split[0]);floatval(split[1]); will ensure that the values are in the correct format.

edited Dec 25, 2013 at 22:33

answered Dec 25, 2013 at 21:21

Caio Oliveira

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2 Comments

Toto Over a year ago

Why do you put \d in character class?

Caio Oliveira Over a year ago

M42 did it to refer to any digit caracter. Instead of [\d] could be also [0-9]

Saurabh Gupta · Accepted Answer · 2013-12-26 19:05:58Z

1

preg_match(/\d{1,}:\d{1,}([.][0-9]{1,})?/s);

edited Dec 26, 2013 at 19:05

answered Dec 25, 2013 at 19:21

Saurabh Gupta

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3 Comments

jamek Over a year ago

/\d{1,}:\d{1,}(?:\.\d{0,2})?/s better

Razorphyn Over a year ago

it validates also: 12:22.23xxxxx

Toto Over a year ago

This doesn't match 25:12 (price without decimal)

revo · Accepted Answer · 2013-12-26 19:25:36Z

0

^\d+:\d+(\.\d{1,2})?$

In:

if(preg_match("/^\d+:\d+(\.\d{1,2})?$/", $str))
{
    echo "Valid input!";
}

Live demo

answered Dec 26, 2013 at 19:25

revo

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Comments

Razorphyn · Accepted Answer · 2013-12-26 19:52:50Z

0

After reading your answers:

/^(\d){1,}?\:(\d){1,}(?:\.(\d){1,2})?$/mi

and this the complete function:

preg_match_all(' /^(\d){1,}?\:(\d){1,}(?:\.(\d){1,2})?$/mi', $_POST['ratetable'], $out);
if($out[0]!=explode("\n",$_POST['ratetable'])){
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(array(0=>'Invalid price table at line: '.implode(", ", array_diff_key(array_flip(explode("\n",$_POST['ratetable'])),array_flip($out[0])))));
    exit();
}

edited Dec 26, 2013 at 19:52

answered Dec 26, 2013 at 11:02

Razorphyn

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