Possible Duplicate:
Transposing multidimensional arrays in PHP
I have three arrays:
$a = (a1, a2, a3);
$b = (b1, b2, b3);
$c = (c1, c2, c3);
I want to combine these arrays to create:
$newa = (a1, b1, c1);
$newb = (a2, b2, c2);
$newc = (a3, b3, c3);
I changed things a little. I didn't use $newA, #newB, $newC, but used a $m array instead.
$a = array( "a1", "a2", "a3");
$b = array( "b1", "b2", "b3");
$c = array( "c1", "c2", "c3");
$count = count($a);
$i = 0;
$m = array();
for($i;$i < $count; $i++) {
$m[] = array( $a[$i], $b[$i], $c[$i]);
}
print_r($m);
Outputs:
Array
(
[0] => Array
(
[0] => a1
[1] => b1
[2] => c1
)
[1] => Array
(
[0] => a2
[1] => b2
[2] => c2
)
[2] => Array
(
[0] => a3
[1] => b3
[2] => c3
)
)
How about this...
<?php
$arr1 = array(1, 2, 3);
$arr2 = array(1, 2, 3);
$arr3 = array(1, 2, 3);
function array_divide() {
$ret = array();
foreach (func_get_args() as $array) {
foreach ($array as $key=>$value) {
$ret[$key][] = $value;
}
}
return $ret;
}
list($new1, $new2, $new3) = array_divide($arr1, $arr2, $arr3);
var_dump($new1);
Obviously the function can only return one value, so you'll need list
if you want to get multiple values out of it.
function transpose(){
$array = func_get_args();
array_unshift($array, null);
return call_user_func_array('array_map', $array);
}
$a = array('a1', 'a2', 'a3');
$b = array('b1', 'b2', 'b3');
$c = array('c1', 'c2', 'c3');
list($newa, $newb, $newc) = transpose($a,$b,$c);
var_dump($newa, $newb, $newc);
Transpose function from here, and slightly modified by me.
Here's my bid. Tried to make it as flexible as possible:
function array_rotate(){
$args = func_get_args();
$argc = func_num_args();
// check if all items are arrays and also get the
// length of the longest array
$maxCount = 0;
foreach ($args as $arg){
if (!is_array($arg))
throw new ArgumentException("array_rotate: All arguments must be arrays");
$_count = count($arg);
if ($_count > $maxCount)
$maxCount = $_count;
}
// setup the returned result
$result = array_fill(0, $argc, array());
// iterate over all items
for ($v = 0; $v < $argc; $v++){
for ($h = 0; $h < $maxCount; $h++){
$result[$h][$v] = isset($args[$v][$h]) ? $args[$v][$h] : null;
}
}
return $result;
}
And example usage:
$newAry = array_rotate(
array('a1','a2','a3'),
array('b1','b2','b3'),
array('c1','c2','c3')
);
// above yields:
Array
(
[0] => Array
(
[0] => a1
[1] => b1
[2] => c1
)
[1] => Array
(
[0] => a2
[1] => b2
[2] => c2
)
[2] => Array
(
[0] => a3
[1] => b3
[2] => c3
)
)
And in cases of uneven arrays, null is returned:
print_r(array_rotate(
array('a1','a2'),
array('b1','b2','b3','b4'),
array('c1','c2','c3')
));
// above yields:
Array
(
[0] => Array
(
[0] => a1
[1] => b1
[2] => c1
)
[1] => Array
(
[0] => a2
[1] => b2
[2] => c2
)
[2] => Array
(
[0] =>
[1] => b3
[2] => c3
)
[3] => Array
(
[0] =>
[1] => b4
[2] =>
)
)