Multidimensional array to text using only keys - php

Question

I have an array of this sort:
$array = [
"Darren" => [
"age" => "18",
"work" => [
"occupation" => "developer",
"company" => "ABC Ltd"
]
],
"John" => [
"age" => "24",
"work" => [
"occupation" => "developer",
"company" => "ABC Ltd",
"url" => "www.example.com"
],
]
]
And would like to merge the keys with a dot in between, depending on the array's hierachy:
"Darren.age"
"Darren.work.occupation"
"Darren.work.company"
...
The function that I made so far is
public function buildExpressionKey($array, $parentKey = null){
$expression = [];
foreach($array as $key=>$value){
if(is_array($value)){
array_push($expression, $parentKey. implode(".",
$this->buildExpressionKey($value, $key)));
}else{
array_push($expression, $key);
}
}
return $expression;
}
it is returning this value at the moment:
[
[0] => "age.Darrenoccupation.company"
[1] => "age.Johnoccupation.company.url"
]
Was wondering if it is possible to make a function which automatically does merges the keys like that, thanks in advance :)

Answer 1

What you are currently asking for:
<?php
$people =
[
'John' =>
[
'Occupation' => 'Developer',
'Age' => 18
],
'Darren' =>
[
'Occupation' => 'Manager',
'Age' => 40
]
];
foreach($people as $name => $value)
foreach($value as $k => $v)
$strings[] = $name . '.' . $k;
var_export($strings);
Output:
array (
0 => 'John.Occupation',
1 => 'John.Age',
2 => 'Darren.Occupation',
3 => 'Darren.Age',
)

Answer 2

Managed to resolve this issue :)
/**
* #param $array
* #return array
*/
public function buildExpressionKey($array){
$iterator = new \RecursiveIteratorIterator(new \RecursiveArrayIterator($array));
$keys = array();
foreach ($iterator as $key => $value) {
// Build long key name based on parent keys
for ($i = $iterator->getDepth() - 1; $i >= 0; $i--) {
$key = $iterator->getSubIterator($i)->key() . '.' . $key;
}
$keys[] = $key;
}
return $keys;
}
Found something similar on here: Get array's key recursively and create underscore separated string