Randomize elements with same value - php

Question

Hello stackoverflow community. I need help with arrays. It's my weakness. I've got this kind of array:
Array
(
[0] => Array
(
[id] => 7
[slot] => 1
[name] => Apple
[start_date] => 12/16/2015
[end_date] => 03/10/2016
[status] => 1
[pre_exp_email] => 0
)
[1] => Array
(
[id] => 8
[slot] => 1
[name] => Cherry
[start_date] => 12/29/2015
[end_date] => 03/20/2016
[status] => 1
[pre_exp_email] => 0
)
[2] => Array
(
[id] => 5
[slot] => 3
[name] => Bananna
[start_date] => 11/30/2015
[end_date] => 00/00/0000
[status] => 1
[pre_exp_email] => 0
)
[3] => Array
(
[id] => 1
[slot] => 4
[name] => Kiwi
[start_date] => 11/21/2015
[end_date] => 12/21/2016
[status] => 1
[pre_exp_email] => 0
)
)
And my job is to randomize elements which has same [slot], but leave order ascending. For example now it is:
1 Apple 1 Cherry 3 Bannana 4 Kiwi
I need to randomize those elements who has same slot number. So Apple and Cherry would swap positions. How can I do this stuff?

Answer 1

Update : Using shuffle & usort :
shuffle($fruits);
function cmp($a, $b) {
if ($a['slot'] == $b['slot']) {
return 0;
}
return ($a['slot'] < $b['slot']) ? -1 : 1;
}
usort($fruits, "cmp");

Answer 2

Make a new array from the original having slot as keys
$elements = array(
0 => Array
(
'id' => 7,
'slot' => 1
),
1 => Array
(
'id' => 8,
'slot' => 1
),
2 => Array
(
'id' => 9,
'slot' => 1
),
3 => Array
(
'id' => 9,
'slot' => 5
)
);
foreach($elements as $element){
$newArray[$element['slot']][] = $element; //put every element having the same slot
}
$elementSlots = array_keys($newArray); // all slots are stored in elementSlots
$Result = array();
foreach($elementSlots as $slot) {
shuffle($newArray[$slot]); //randomize elements having the same slot
foreach($newArray[$slot] as $element) { //add them to the result array
$Result[$slot][] = $element;//For output 1
//$Result[] = $element; //For output 2
}
}
var_dump($Result);
Output 1:
array (size=2)
1 =>
array (size=3)
0 =>
array (size=2)
'id' => int 7
'slot' => int 1
1 =>
array (size=2)
'id' => int 9
'slot' => int 1
2 =>
array (size=2)
'id' => int 8
'slot' => int 1
5 =>
array (size=1)
0 =>
array (size=2)
'id' => int 9
'slot' => int 5
Output 2:
array (size=4)
0 =>
array (size=2)
'id' => int 7
'slot' => int 1
1 =>
array (size=2)
'id' => int 9
'slot' => int 1
2 =>
array (size=2)
'id' => int 8
'slot' => int 1
3 =>
array (size=2)
'id' => int 9
'slot' => int 5