Split array into a unspecific number of chuncks - php

Question

I have a string that contains the given answers from a qiuz by a user. This string is saved on the db table and it has this form.
,P1,1,2,3,5,8,9,,P2,1,3,4,5,6,8,9,,P3,1,2,3,4,6,8,9,,P4,1,,P5a,b,,P5b,d,,P5c,a,,P5d,c,,P6,4,,P7,2,,P8a,hc,,P8b,df,,P8c,bg,,P8d,e,,P9,4,,P10,3,,P11,4,,P12,2,,P13,3,,P14,3,,P15a,acejg,,P15b,dfhib,,P16,1,3,,P17,2,,P18,1,,P19,3,,P20,3,5,6
Ater getting the string i explode it, and the form becomes like this.
Array
(
[0] => P1
[1] => 1
[2] => 2
[3] => 3
[4] => 5
[5] => 8
[6] => 9
[7] => P2
[8] => 1
[9] => 3
[10] => 4
[11] => 5
[12] => 6
[13] => 8
[14] => 9
[15] => P3
[16] => 1
[17] => 2
[18] => 3
[19] => 4
[20] => 6
[21] => 8
[22] => 9
[23] => P4
[24] => 1
[25] => P5a
[26] => b
[27] => P5b
[28] => d
[29] => P5c
[30] => a
[31] => P5d
[32] => c
[33] => P6
[34] => 4
[35] => P7
[36] => 2
[37] => P8a
[38] => hc
[39] => P8b
[40] => df
[41] => P8c
[42] => bg
[43] => P8d
[44] => e
[45] => P9
[46] => 4
[47] => P10
[48] => 3
[49] => P11
[50] => 4
[51] => P12
[52] => 2
[53] => P13
[54] => 3
[55] => P14
[56] => 3
[57] => P15a
[58] => acejg
[59] => P15b
[60] => dfhib
[61] => P16
[62] => 1
[63] => 3
[64] => P17
[65] => 2
[66] => P18
[67] => 1
[68] => P19
[69] => 3
[70] => P20
[71] => 3
[72] => 5
[73] => 6
)
each question starts with a "P". So question 1 will be "P1" question 2 "P2" and so on.
Each given answer is between the "P" until next "P".
So the answers given from the user for the question number 1 are " 1 | 2 | 3 | 5 | 8 | 9 ".
I was trying to insert the values to another array with a foreach loop but i could not find any way to seperate the answers.
My desire output is.
Array
(
[P1] => Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 5
[4] => 8
[5] => 9
)
[P2] => Array
(
[0] => 3
[1] => 4
[2] => 5
[3] => 6
[4] => 8
[5] => 9
)
)
Please tell me if you have any suggestions.Thank you very much

Answer 1

assuming we ve everything inside $p
$res= array();
foreach($p as $key => $value){
if(strpos($value, "P") !== false){
$currentP = $value;
$res[$currentP] = array();
}elseif($value){
$res[$currentP][] = $value;
}
}
WORKING PHP FIDDLE tested with v5 and v7

Answer 2

This seems to work :
<?php
$string = ',P1,1,2,3,5,8,9,,P2,1,3,4,5,6,8,9,,P3,1,2,3,4,6,8,9,,P4,1,,P5a,b,,P5b,d,,P5c,a,,P5d,c,,P6,4,,P7,2,,P8a,hc,,P8b,df,,P8c,bg,,P8d,e,,P9,4,,P10,3,,P11,4,,P12,2,,P13,3,,P14,3,,P15a,acejg,,P15b,dfhib,,P16,1,3,,P17,2,,P18,1,,P19,3,,P20,3,5,6';
$array = explode(',', $string);
$return = array();
$index = '';
foreach ($array as $v) {
if (trim($v) == '') // Skip empty values
continue;
if (substr($v, 0, 1) == 'P') {
$index = $v;
if (!isset($return[$index]))
$return[$index] = array();
} else {
$return[$index][] = $v;
}
}
var_dump($return);
?>

Answer 3

this could be an approach
<?php
$string = ',,P1,1,2,3,5,8,9,,P2,1,3,4,5,6,8,9,,P3,1,2,3,4,6,8,9,,P4,1,,P5a,b,,P5b,d,,P5c,a,,P5d,c,,P6,4,,P7,2,,P8a,hc,,P8b,df,,P8c,bg,,P8d,e,,P9,4,,P10,3,,P11,4,,P12,2,,P13,3,,P14,3,,P15a,acejg,,P15b,dfhib,,P16,1,3,,P17,2,,P18,1,,P19,3,,P20,3,5,6';
$sepAns = explode(',,',$string);
echo $sepAns[2];
?>
Note that I added a , at the beginning to maintain integrity of ',,'

Answer 4

$str = ',P1,1,2,3,5,8,9,,P2,1,3,4,5,6,8,9,,P3,1,2,3,4,6,8,9,,P4,1,,P5a,b,,P5b,d,,P5c,a,,P5d,c,,P6,4,,P7,2,,P8a,hc,,P8b,df,,P8c,bg,,P8d,e,,P9,4,,P10,3,,P11,4,,P12,2,,P13,3,,P14,3,,P15a,acejg,,P15b,dfhib,,P16,1,3,,P17,2,,P18,1,,P19,3,,P20,3,5,6';
$arr = explode( ',', $str );
$structuredArr = array();
foreach ( $arr AS $element ) {
if ( ( strpos( $element, 'P' ) === FALSE ) === FALSE ) {
$key = $element;
$structuredArr[ $key ] = array();
} else {
if ( isset( $key ) ) {
if ( !empty( $element ) ) {
$structuredArr[ $key ][] = $element;
}
}
}
}