get a set of values from an array - php

Question

i have a set of arrays:
$nums = array(2,3,1);
$data = array(11,22,33,44,55,66);
what i want to do is to get a set of $data array from each number of $nums array,
the output must be:
output:
2=11,22
3=33,44,55
1=66
what i tried so far is to slice the array and remove the sliced values from an array but i didn't get the correct output.
for ($i=0; $i < count($nums); $i++) {
$a = array_slice($data,0,$nums[$i]);
for ($x=0; $x < $nums[$i]; $x++) {
unset($data[0]);
}
}

Answer 1

Another alternative is to use another flavor array_splice, it basically takes the array based on the offset that you inputted. It already takes care of the unsetting part since it already removes the portion that you selected.
$out = array();
foreach ($nums as $n) {
$remove = array_splice($data, 0, $n);
$out[] = $remove;
echo $n . '=' . implode(',', $remove), "\n";
}
// since nums has 2, 3, 1, what it does is, each iteration, take 2, take 3, take 1
Sample Output
Also you could do an alternative and have no function usage at all. You'd need another loop though, just save / record the last index so that you know where to start the next num extraction:
$last = 0; // recorder
$cnt = count($data);
for ($i = 0; $i < count($nums); $i++) {
$n = $nums[$i];
echo $n . '=';
for ($h = 0; $h < $n; $h++) {
echo $data[$last] . ', ';
$last++;
}
echo "\n";
}

Answer 2

You can array_shift to remove the first element.
$nums = array(2,3,1);
$data = array(11,22,33,44,55,66);
foreach( $nums as $num ){
$t = array();
for ( $x = $num; $x>0; $x-- ) $t[] = array_shift($data);
echo $num . " = " . implode(",",$t) . "<br />";
}
This will result to:
2 = 11,22
3 = 33,44,55
1 = 66

Answer 3

This is the easiest and the simplest way,
<?php
$nums = array(2,3,1);
$data = array(11,22,33,44,55,66);
$startingPoint = 0;
echo "output:"."\n";
foreach($nums as $num){
$sliced_array = array_slice($data, $startingPoint, $num);
$startingPoint = $num;
echo $num."=".implode(",", $sliced_array)."\n";
}
?>