PHP split string into integer element and string

I have a string say: Order_num = "0982asdlkj"

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

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 between 1 and 4 and the letters are random after that, so no way to split at a particular letter. Please help as specifically as possible!

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