I have this multidimensional array
$liste = [[1,2,3],5,[['x','y','z'],true]];
and I want to change it to one dimensionel array
$liste = [1,2,3,5,'x','y','z',true];
so i always have a problem that give me the same shape
function to_array($list){
$out=[];
if(!is_array($list)){
return $list;
}else{
foreach($list as $line){
$out[]= to_array($line);
}
}
return $out;
}
where is the problem in this recursive function !!!
The issue with your code is that you are pushing the result of to_array into $out, when what you want to do is use array_merge. Now since that requires both parameters to be arrays, when $list is not an array, you need to return an array containing the individual value. So change these lines:
return $list;
$out[]= to_array($line);
To:
return array($list);
$out = array_merge(to_array($line));
i.e.
function to_array($list){
$out=[];
if(!is_array($list)){
return array($list);
}else{
foreach($list as $line){
$out = array_merge($out, to_array($line));
}
}
return $out;
}
And you will get the result that you want:
var_export(to_array($liste));
Output:
array (
0 => 1,
1 => 2,
2 => 3,
3 => 5,
4 => 'x',
5 => 'y',
6 => 'z',
7 => true,
)
array_walk_recursive() delivers the desired result from an array of indeterminate depth in a one-liner because it only visits the "leaf-nodes" -- effectively, you don't need to bother checking if an element is or is not an array.
array_walk_recursive() doesn't return an array, it returns true|false based on whether or not there was a failure.
&$flat is a variable which is "passed by reference". This means that $flat can act as a vehicle to transport the data from inside the function scope to outside the function scope. As the elements are traversed, each new value is pushed into $flat using square bracket syntax.
This is exactly what this function does best -- use it.
Code: (Demo)
$liste = [[1, 2, 3], 5, [['x', 'y', 'z'], true]];
array_walk_recursive($liste, function($v) use (&$flat){ $flat[] = $v; });
var_export($flat);
Output:
array (
0 => 1,
1 => 2,
2 => 3,
3 => 5,
4 => 'x',
5 => 'y',
6 => 'z',
7 => true,
)
