Split alphanumeric string between leading digits and trailing letters

I have a string like:

$Order_num = "0982asdlkj";

How can I split that into the 2 variables, with the number as one element and then another variable with the letter element?

The number element can be any length from 1 to 4 say and the letter element fills the rest to make every order_num 10 characters long in total.

I have found the php explode function...but don't know how to make it in my case because the number of numbers is betwee开发者_运维问答n 1 and 4 and the letters are random after that, so no way to split at a particular letter.

You can use preg_split using lookahead and lookbehind:

print_r(preg_split('#(?<=\d)(?=[a-z])#i', "0982asdlkj"));

prints

Array
(
    [0] => 0982
    [1] => asdlkj
)

This only works if the letter part really only contains letters and no digits.

Update:

Just to clarify what is going on here:

The regular expressions looks at every position and if a digit is before that position ((?<=\d)) and a letter after it ((?=[a-z])), then it matches and the string gets split at this position. The whole thing is case-insensitive (i).

Use preg_match() with a regular expression of (\d+)([a-zA-Z]+). If you want to limit the number of digits to 1-4 and letters to 6-9, change it to (\d+{1,4})([a-zA-Z]{6,9}).

preg_match("/(\\d+)([a-zA-Z]+)/", "0982asdlkj", $matches);
print("Integer component: " . $matches[1] . "\n");
print("Letter component: " . $matches[2] . "\n");

Outputs:

Integer component: 0982
Letter component: asdlkj

http://ideone.com/SKtKs

You can also do it using preg_split by splitting your input at the point which between the digits and the letters:

list($num,$alpha) = preg_split('/(?<=\d)(?=[a-z]+)/i',$Order_num);

You can use a regex for that.

preg_match('/(\d{1,4})([a-z]+)/i', $str, $matches);
array_shift($matches);
list($num, $alpha) = $matches;

Check this out

<?php
$Order_num = "0982asdlkj";
$split=split("[0-9]",$Order_num);
$alpha=$split[(sizeof($split))-1];
$number=explode($alpha, $Order_num);
echo "Alpha -".$alpha."<br>";
echo "Number-".$number[0];
?>

with regards

wazzy

My preferred approach would be sscanf() because it is concise, doesn't need regex, offers the ability to cast the numeric segment as integer type, and doesn't generate needless fullstring matches like preg_match(). %s does rely, though, on the fact that there will be no whitespaces in the letters segment of the string.

Demo

$Order_num = "0982asdlkj";
var_export (
    sscanf($Order_num, '%d%s')
);

This can also be set up to declare individual variables.

sscanf($Order_num, '%d%s', $numbers, $letters)

If wanting to use a preg_ function, preg_split() is most appropriate, but I wouldn't use expensive lookarounds. Match the digits, then forget them (with \K). This will split the string without consuming any characters. Demo

var_export (
    preg_split('/\d+\K/', $Order_num)
);

To assign variables, use "symmetric array destructuring".

[$numbers, $letters] = preg_split('/\d+\K/', $Order_num);

Beyond these single function approaches, there will be MANY two function approaches like:

$numbers = rtrim($Order_num, 'a..z');
$letters = ltrim($Order_num, '0..9');

But I wouldn't use them in a professional script because they lack elegance.