Splitting GET string - php

Question

I need to split my GET string into some array. The string looks like this:
ident[0]=<IDENT_0>&value[0]=<VALUE_0>&version[0]=<VERSION_0>&....&ident[N]=<IDENT_N>&value[N]=<VALUE_N>&version[N]=<VERSION_N>
So, I need to split this string by every third ampersand character, like this:
ident[0]=<IDENT_0>&value[0]=<VALUE_0>&version[0]=<VERSION_0>
ident[1]=<IDENT_1>&value[1]=<VALUE_1>&version[1]=<VERSION_1> and so on...
How can I do it? What regular expression should I use? Or is here some better way to do it?

Answer 1

There is a better way (assuming this is data being sent to your PHP page, not some other thing you're dealing with).
PHP provides a "magic" array called $_GET which already has the values parsed out for you.
For example:
one=1&two=2&three=3
Would result in this array:
Array ( [one] => 1 [two] => 2 [three] => 3 )
So you could access the variables like so:
$oneValue = $_GET['one']; // answer is 1
$twoValue = $_GET['two']; // and so on
If you provide array indexes, which your example does, it'll sort those out for you as well. So, to use your example above $_GET would look like:
Array
(
[ident] => Array
(
[0] => <IDENT_0>
[N] => <IDENT_N>
)
[value] => Array
(
[0] => <VALUE_0>
[N] => <VALUE_N>
)
[version] => Array
(
[0] => <VERSION_0>
[N] => <VERSION_N>
)
)
I'd assume your N keys will actually be numbers, so you'll be able to look them up like so:
$_GET['ident'][0] // => <IDENT_0>
$_GET['value'][0] // => <VALUE_0>
$_GET['version'][0] // => <VERSION_0>
You could loop across them all or whatever, and you will never have to worry about splitting them all out yourself.
Hope it helps you.

Answer 2

You can use preg_split with this pattern: &(?=ident)
$result = preg_split('~&(?=ident)~', $yourstring);
regex detail: &(?=ident) means & followed by ident
(?=..) is a lookahead assertion that performs only a check but match nothing.
Or using preg_match_all:
preg_match_all('~(?<=^|&)[^&]+&[^&]+&[^&]+(?=&|$)~', $yourstring, &matches);
$result = $matches[0];
pattern detail: (?<=..) is a lookbehind assertion
(?<=^|&) means preceded by the begining of the string ^ or an ampersand.
[^&]+ means all characters except the ampersand one or more times.
(?=&|$) means followed by an ampersand or the end of the string $.
Or you can use explode, and then a for loop:
$items = explode('&', $yourstring);
for ( $i=0; $i<sizeof($items); $i += 3 ) {
$result[] = implode('&', array_slice($items, $i, 3));
}