unset inside eval not working - php

Question

I'm trying to remove an item from an array based on string;
public function delete($path){
// a key path given
if(strpos($path, '.') !== false){
$parts = explode('.', $path);
$first_key = array_shift($parts);
$data = $this->get($path);
// first key doesn't exist
if($data === false)
return false;
$parts = implode('"]["', $parts);
if(eval('if(isset($data["'.$parts.'"])){ unset($data["'.$parts.'"]); return true; } return false;'))
return $this->set($first_key, $data);
}
// a single key given
if(isset($this->data[$path]){
unset($this->data[$path]);
return true;
}
return false;
}
And it only works for single keys. Apparently the eval doesn't modify $data for some reason.
delete('test') works, but delete('test.child') doesn't...

Answer 1

I don't see why you'd need eval() here. See the following to replace your eval() construct:
<?php
function removeFromArray(&$array, $path)
{
if (!is_array($path)) {
$path = explode('.', trim($path, '.'));
}
$current = &$array;
while ($path) {
$key = array_shift($path);
// isset() would fail on `$array[$key] === null`
if (!array_key_exists($key, $current)) {
// abort if the array element does not exist
return false;
}
if (!$path) {
// reached the last element
unset($current[$key]);
return true;
}
if (!is_array($current[$key])) {
// can't go deeper, so abort
return false;
}
// continue with next deeper element
$current = &$current[$key];
}
return false;
}
$data = array(
'a' => 1,
'b' => array(
'c' => 2,
'd' => 3,
'e' => array(
'f' => 4,
),
),
);
var_dump(
removeFromArray($data, 'b.e.f'),
$data,
removeFromArray($data, 'b.c'),
$data
);

Answer 2

function unset_multiple($arr = [], $keys = [], $limitKeys = 30){
if($keys && count($keys) <= $limitKeys && is_array($arr) && count($arr) > 0){
foreach($keys as $key){
$keys[$key] = null;
}
return array_diff_key($arr, $keys);
} else{
throw new Exception("Input array is invalid format or number of keys to remove too large");
}
}
Example called:
$arr = array("name" => "Vuong", "age" => 20, "address" => "Saigon");
$res = unset_multiple($arr, ["name", "age"]);
//Result: ["address" => "Saigon"]
Make sure $keys param has all available keys in $arr param (only two-dimensional arrays). Need to remember this function is a helper to quickly removing multiple elements of array, not a function returns the absolute accurate results for all cases.