php split array between two values - php

Question

i have an array like:
Array ( [0] => #!A1#DC [1] => #IMSR102.71/74.82 [2] => #HV50 [3] => #PR7/7/ [4] => #RX0 [5] => #ERN/1//0 [6] => #Q2 [7] => #!A1#DC [8] => #IMSR102.50/74.82 [9] => #HV40 [10] => #PR5/5/ [11] => #RX0 [12] => #ERN/1//1 [13] => #Q2 etc etc with hundreds o values
i get this array from a file (with the function file($filename) ) and i need to split it in many subarray.
"!A1#DC" this is the beginning of a series of values ​​that ends with #Q2 but the number of the values between the beginning and the end is not always the same and the only 2 values that are same are the two given ("!A1#DC" for the beginning and "#Q2" for the end)
how can i get somethings like this?
Array (
[0] => Array ( [0] => #!A1#DC [1] => #IMSR102.71/74.82 [2] => #HV50 [3] => #PR7/7/ [4] => #RX0 [5] => #ERN/1//0 [6] => #Q2 )
[1] => Array (
[1] => #!A1#DC [2] => #IMSR102.50/74.82 [3] => #HV40 [4] => #PR5/5/ [5] => #RX0 [6] => #ERN/1//1 [7] => #Q2 etc etc
could you please help me?
thanks

Answer 1

Loop through an array. When you meet starting value, store it's index. When you meet ending value, use array_slice() to extract the part between the last pair of starting and ending values, store this part into another array.
$source = array (
'#!A1#DC',
'#IMSR102.71/74.82',
'#HV50',
'#PR7/7/',
'#RX0',
'#ERN/1//0',
'#Q2',
'#!A1#DC',
'#IMSR102.50/74.82',
'#HV40',
'#PR5/5/',
'#RX0',
'#ERN/1//1',
'#Q2',
);
$dest = array();
$startValue = '#!A1#DC';
$endValue = '#Q2';
$startIndex = 0;
foreach ( $source as $index => $value ) {
if ( $value === $startValue ) {
$startIndex = $index;
} else
if ( $value === $endValue ) {
$dest[] = array_slice($source, $startIndex, $index - $startIndex + 1);
}
}
print_r($dest);

Answer 2

Basically you need to loop through each element of $input, collecting those within START and END elements into a separate array:
$input = array("#!A1#DC", "A", "B", "#Q2");
$values = array();
$current = 0;
define("START", "#!A1#DC");
define("END", "#Q2");
for ($i = 0; $i < count($input); $i++) {
if ($input[$i] == END) {
// Ignore any elements after this point until we see START
$current = null;
} else if ($input[$i] == START) {
// Create a new current collection array
$current = count($values);
$values[$current] = array();
} else {
// Store the value if we are collecting
if ($current !== null) {
$values[$current][] = $input[$i];
}
}
}