[SOLVED] matching 999 or 1,123 number formats

[daydreamer]

Hello.

 

I am trying to match either a 3 digit number or a 4 digit in this format: "1,123".

 

This is what I have:

 

<?php
preg_match("~(\d?,?\d\d\d)~i", $searchhere, $matches);
?>

 

It matches 3 digit numbers fine. But something like "1,123" will return "123".

 

Whats up with this?!

 

[cags]

Not on my computer... I tested your code with a $searchere value of "1,123" and it returned "1,123";

[daydreamer]

yeh that wasnt the full code thats the part where I thought it was.

 

I had something similar to:

<?php
preg_match("~.*(\d?,?\d\d\d)~i", $searchhere, $matches);
?>

 

I think the .* was matching some of the numbers so it wasnt returning them all.

 

Thanks for the test!

[nrg_alpha]

In it's rawest form:

 

$str = 'blah 1,234 more blah';
preg_match('#(?:\d,)?\d{3}#', $str, $match);
echo $match[0];

 

However, if it encounters a number like 1234, it will match 123 (which I assume is not desirable). So perhaps we can also make use of a conditional and \D:

 

$str = 'blah 1,234 more blah';
if(preg_match('#\D(?:\d,)?\d{3}\D#', $str, $match)){
    echo $match[0];
} else {
    echo 'No proper format found.';
}

 

But I suppose this highly depends on the circumstances of where the 3 or 4 digit number is situated within the string. If the numbers are at the beginning of the string, the initial \D will throw it off. If that's the case, the pattern could be amended to:

 

#(^|\D)(?:\d,)?\d{3}\D#

 

In either case, I noticed you made use of the 'i' modifier, which is not usable in your example, as this is case insensative.. but since you are using digits and commas, the 'i' doesn't perform anything.

 

EDIT - An even more refined method based off the last one:

if(preg_match('#(?:^|\D)\K(?:\d,)?\d{3}(?=\D|$)#', $str, $match)){

 

This will now match those numbers at the start or at the end of a string.

[daydreamer]

thanks for your solutions..

 

What does \D do?

[nrg_alpha]

\D = a character that is not a digit (the inverse of \d if you will)