Method to change specific value inside multidimensional array - php

Question

Given a class with a multidimensional array as private property.
I'm trying to write a method setValue() which could change any value of this private array by passing:
some kind of path to a specific value (e.g. $path = ['lorem' => ['ipsum' => ['dolor' => ['sit' => null]]]];)
the new value
...
Class Tree {
private $tree = array(
'lorem' => array(
'ipsum' => array(
'dolor' => array(
'sit' => 'old value'
)
),
'amet' => array(
'consetetur' => array(
'sadipscing' => 'another value'
)
)
)
);
// setValue has to be a recursive function I guess
public function setValue($path, $value) {
// ???
}
public function getTree() {
return $this->tree;
}
}
Thanks to a comment of Gabriel on php.net I was able to find a working solution.
You can see my solution among the answers below.
What I actualy want to know: What are alternative approaches?

Answer 1

There are some recursive array built-in functions that may help you here:
<?php
class Tree
{
private $tree =
[
'foo' =>
[
'bar' => 'baz',
'qux' => 'quux'
]
];
public function replaceLeaf($key, $value) {
array_walk_recursive(
$this->tree,
function(&$item, $index) use ($key, $value) {
if($key === $index)
$item = $value;
}
);
}
public function replace($value) {
$this->tree = array_replace_recursive(
$this->tree,
$value
);
}
public function getTree()
{
return $this->tree;
}
}
$tree = new Tree;
$tree->replaceLeaf('bar', 'stool');
$tree->replace(
['foo' => ['qux' => 'quack']]
);
var_export($tree->getTree());
Output:
array (
'foo' =>
array (
'bar' => 'stool',
'qux' => 'quack',
),
)
However looking at your original question targeting the array is likely an easier syntax, especially if you are only changing one attribute at a time. You'd have to change the visibility of the array accordingly:
$tree->tree['foo']['qux'] = 'whatever';

Answer 2

With the decisive hint from gabriel.sobrinho#gmail.com at www.php.net
The method rebuildTree does the job. But it doesn't just change a value in $this->tree. It creates a new array.
Class Tree {
private $tree = array(
'lorem' => array(
'ipsum' => array(
'dolor' => array(
'sit' => 'old value'
)
),
'amet' => array(
'consetetur' => array(
'sadipscing' => 'another value'
)
)
)
);
public function setValue(array $path_and_value) {
$this->tree = $this->rebuildTree($this->tree, $path_and_value);
}
public function getTree() {
return $this->tree;
}
private function rebuildTree(array $arr, array $path_and_value) {
foreach($path_and_value AS $key => $value) {
if(
is_array($value)
&& isset($arr[$key])
) {
$arr[$key] = $this->rebuildTree($arr[$key], $value);
}
else {
$arr[$key] = $value;
}
}
return $arr;
}
}
$Tree = new Tree();
$path_and_value = array(
'lorem' => array(
'ipsum' => array(
'dolor' => array(
'sit' => 'new value'
)
)
)
);
$Tree->setValue($path_and_value);
print_r($Tree->getTree());
// ['lorem' => ['ipsum' => ['dolor' => ['sit' => 'new value']]]]