Many times we need to turn multidimensional arrays into one-dimensional arrays, because we only need one-dimensional arrays, and a one-dimensional array is more convenient to use, how do you turn a multidimensional array into a one-dimensional array in PHP? Let's take a look at three multidimensional arrays as examples of one-dimensional arrays:
First, use foreach
Copy Code code as follows:
<?php
function Arr_foreach ($arr)
{
Static $tmp =array ();
if (!is_array ($arr))
{
return false;
}
foreach ($arr as $val)
{
if (Is_array ($val))
{
Arr_foreach ($val);
}
Else
{
$tmp []= $val;
}
}
return $tmp;
}
$a = Array (1,2=>array (3,4=>array (5,6)), 7);
Print_r (Arr_foreach ($a));
?>
using a For loop, you can only traverse the array of numeric subscripts
Copy Code code as follows:
<?php
function Arr_foreach ($arr)
{
Static $tmp =array ();
for ($i =0; $i <count ($arr); $i + +)
{
if (Is_array ($arr [$i]))
{
Arr_foreach ($arr [$i]);
}else{
$tmp []= $arr [$i];
}
}
return $tmp;
}
Call Example
$a = Array (1,array (3,array (5,6)), 7);
Print_r (Arr_foreach ($a));
?>
third, use while
Copy Code code as follows:
/**
* Convert a multidimensional array to a one-dimensional array
* @author Echo
* @link http://www.jb51.net/
* @param array $arr
* @return Array
*/
function Arrmd2ud ($arr) {
#将数值第一元素作为容器, to assign a value to the address.
$ar _room = & $arr [key ($arr)];
#第一容器不是数组进去转呀
if (!is_array ($ar _room)) {
#转为成数组
$ar _room = Array ($ar _room);
}
#指针下移
Next ($arr);
#遍历
while (the list ($k, $v) = each ($arr)) {
#是数组就递归深挖, not just the group.
$v = Is_array ($v)? Call_user_func (__function__, $v): Array ($v);
#递归合并
$ar _room = array_merge_recursive ($ar _room, $v);
#释放当前下标的数组元素
Unset ($arr [$k]);
}
return $ar _room;
}
Call Example:
Copy Code code as follows:
$arr = Array (1, 2, 3 => Array (1, 2, ' AR ' => array (1, 2 => Array (' A ', ' B ')), array (' AR ' => Array (3, 4)));
Print_r (Arrmd2ud ($arr));
Output:
Copy Code code as follows:
Array
(
[0] => 1
[1] => 2
[2] => 1
[3] => 2
[4] => 1
[5] => A
[6] => b
[7] => 3
[8] => 4
)
