Combining of array items - php

Question

I have a problem with an advanced loop, this are my arrays
$array1 = array(1,2,3);
$array2 = array(4,5);
$array3 = array(6,7,8,9);
$array4 = array(10,11);
I want to loop with the following result:
1,4,6,10
1,4,6,11
1,4,7,10
1,5,7,11
With the last: 3,5,8,11
How can I do that?

Answer 1

Solution for a variable number of arrays. Can probably be written a bit shorter, but I leave that to you. ;)
<?php
$array1 = array(1,2,3);
$array2 = array(4,5);
$array3 = array(6,7,8,9);
$array4 = array(10,11);
function turboArray()
{
$arrays = func_get_args();
$indexes = array_fill(0, count($arrays), 0);
function turboSubArray(&$arrays, &$indexes, $l){
for ($a = 0; $a < count($arrays[$l]); $a++){
$indexes[$l] = $a;
if ($l == count($arrays) - 1) {
for ($i = 0; $i < count($indexes); $i++)
{
echo $arrays[$i][$indexes[$i]];
if ($i == count($indexes) - 1){
echo "\n<br/>";
$indexes[$i] = 0;
if ($i == 0) return;
}
else {
echo ', ';
}
}
} else if ($l < count($indexes)) {
turboSubArray($arrays, $indexes, $l + 1);
}
}
}
$l = 0;
turboSubArray($arrays, $indexes, $l);
}
turboArray($array1, $array2, $array3, $array4);

Answer 2

This should do it... ?
foreach ($array1 as $first) {
foreach ($array2 as $second) {
foreach ($array3 as $third) {
foreach ($array4 as $fourth) {
echo "$first $second $third $fourth";
}
}
}
}

Answer 3

I got bored and decided to overengineer a bit. Enjoy.
class CrossJoin implements Iterator {
private $arrays = array();
private $index = 0;
public function __construct(/* $array1, ... */) {
foreach (func_get_args() as $arr) {
// ArrayIterator's iteration stuff is cleaner than arrays',
// and less prone to breakage when objects are passed around
if (count($arr)) $this->arrays[] = new ArrayIterator($arr);
}
// if any of the arrays were empty, a cross join should fail.
// fudge a single empty array to prevent special-casing later
if (count($this->arrays) !== func_num_args()) {
$this->arrays = array(new ArrayIterator(array()));
}
}
public function next() {
for ($i = count($this->arrays) - 1; $i >= 0; --$i) {
// carry til we don't have to anymore
$place = $this->arrays[$i];
$place->next();
if ($place->valid()) break;
}
// if $i<0, then we carried right off the edge of the list.
// don't let $arrays[0] be reset, cause that's our indicator
// that we're done.
if ($i<0) return;
++$this->index;
for (++$i; $i < count($this->arrays); ++$i) {
$this->arrays[$i]->rewind();
}
}
public function current() {
$result = array();
foreach ($this->arrays as $arr) { $result[] = $arr->current(); }
return $result;
}
public function key() { return $this->index; }
public function valid() {
return !empty($this->arrays) && $this->arrays[0]->valid();
}
public function rewind() {
foreach ($this->arrays as $arr) $arr->rewind();
$this->index = 0;
}
}
$combos = new CrossJoin(
array(1, 2, 3),
array(4, 5),
array(6, 7, 8, 9),
array(10, 11)
);
foreach ($combos as $combo) {
echo implode(', ', $combo), "\n";
}

Answer 4

Hope that helps:
for ($i = 0; $i < count($a1); ++i) {
for ($j = 0; $j < count($a2); ++j) {
for ($k = 0; $k < count($a3); ++k) {
for ($l = 0; $l < count($a4); ++l) {
echo $a1[$i] . ' ' . $a2[$j] . ' ' . $a3[$k] . ' ' . $a4[$l] . '\n';
}
}
}
}
Cheers!

Answer 5

You are looking for the PHP array_merge function.