Select and delete random keys from multidimensional array - php

Question

I have one problem with randomness.
I have example array.
$example=array(
'F1' => array('test','test1','test2','test5'),
'F2' => array('test3', 'test4'),
'F3' => array('one','twoo','threee','x'),
'F5' => array('wow')
)
I want to choose random keys from array to other array with specified size. In this second array I want values from other groups.
For example i got
$amounts = array(4,3,1,2,1);
I want to choose randomly specified ammount of variables ($amount) from $example, but of course - always from other groups.
Example result:
$result=(
array(4) => ('test','test4','x','wow'),
array(3) => ('test2','test3','three'),
array(1) => ('test1')
array(2) => ('test5','one')
array(1) => ('twoo')
What I tried so far?
foreach($amounts as $key=>$amount){
$random_key[$key]=array_rand($example,$amount);
foreach($result[$key] as $key2=>$end){
$todelete=array_rand($example[$end]);
$result[$key][$key2]=$example[$amount][$todelete]
}
}
I don't know now, what to fix or to do next.
Thanks for help!

Answer 1

$example = array(
'F1' => array('test', 'test1', 'test2', 'test5'),
'F2' => array('test3', 'test4'),
'F3' => array('one', 'twoo', 'threee', 'x'),
'F5' => array('wow')
);
$amounts = array(4, 3, 1, 2, 1);
$result = array();
$example = array_values($example);
//randomize the array
shuffle($example);
foreach ($example as $group) {
shuffle($group);
}
//sort the example array by child length
usort($example, function ($a, $b) {
return count($b) - count($a);
});
foreach ($amounts as $amount) {
$tmpResult = array();
for ($i = 0; $i < $amount; $i++) {
if(empty($example[$i])){
throw new \InvalidArgumentException('The total number of values in the array exceed the amount inputed');
}
$tmpResult[] = array_pop($example[$i]);
}
$result[] = $tmpResult;
//sort the example array again by child length
usort($example, function ($a, $b) {
return count($b) - count($a);
});
}
print_r($result);
test result:
Array
(
[0] => Array
(
[0] => test5
[1] => x
[2] => test4
[3] => wow
)
[1] => Array
(
[0] => test2
[1] => threee
[2] => test3
)
[2] => Array
(
[0] => test1
)
[3] => Array
(
[0] => twoo
[1] => test
)
[4] => Array
(
[0] => one
)
)