convert a variable to an array in php - php

Question

I have this Variable :
$value = '"item_id"=>"null","parent_id"=>"none","depth"=>0,"left"=>"1","right"=>18';
And I want get item_id and other element from top Variable with Array method, so i write this :
$value_arr = array($value);
$item_id = $value_arr["item_id"];
but i get error Notice: Undefined index: item_id in file.php on line 115
but When i use this method i get fine result successfully :
$value_arr = array("item_id"=>"null","parent_id"=>"none","depth"=>0,"left"=>"1","right"=>18);
$item_id = $value_arr["item_id"];
How i can solve this problem ?
Note: i don't want use 2'nd method because my Variables is Dynamic
UPDATE:
Vincent answered that i must use json_decode and i want to ask another question for better way because my original string that i have is :
[
{"item_id":null,"parent_id":"none","depth":0,"left":"1","right":18},
{"item_id":"1","parent_id":null,"depth":1,"left":2,"right":7},
{"item_id":"3","parent_id":null,"depth":1,"left":2,"right":7}
]
With this information whats the better way for get item_id, parent_id and ... ?

Answer 1

$value = '"item_id"=>"null","parent_id"=>"none","depth"=>0,"left"=>"1","right"=>18';
Is not a PHP array, you will need to convert that to an array by exploding it on "=>" and "," and remove any extra "'s you find.
You should be using JSON however and using json_encode and json_decode

Answer 2

Use json_decode() with second parameter as TRUE to get an associative array as result:
$json = json_decode($str, TRUE);
for ($i=0; $i < count($json); $i++) {
$item_id[$i] = $json[$i]['item_id'];
$parent_id[$i] = $json[$i]['parent_id'];
// ...
}
If you want to do it using a foreach loop:
foreach ($json as $key => $value) {
echo $value['item_id']."\n";
echo $value['parent_id']."\n";
// ...
}
Demo!

Answer 3

You should use JSON encoding and use the json_decode method if you want something dynamic. JSON is a good standard for dynamic data.
http://php.net/manual/en/function.json-decode.php

Answer 4

I tested this for you:
<?php
$value = '"item_id"=>"null","parent_id"=>"none","depth"=>0,"left"=>"1","right"=>18';
eval("\$value_arr = array($value);");
print_r($value_arr);
?>
Please check. PHP::eval() is used. It worked.

Answer 5

This can be a solution you are looking for:
<?php
$value = '"item_id"=>"null","parent_id"=>"none","depth"=>0,"left"=>"1","right"=>18';
$arr = explode(',',$value);
foreach($arr as $val)
{
$tmp = explode("=>",$val);
$array[$tmp[0]] = $tmp[1];
}
print_r($array);
?>
And this will output something like:
Array ( ["item_id"] => "null" ["parent_id"] => "none" ["depth"] => 0 ["left"] => "1" ["right"] => 18 )

Answer 6

A quick and dirty solution could be:
$array = json_decode( '{' . str_ireplace( '=>', ':', $value ) . '}', true );
// Array ( [item_id] => null [parent_id] => none [depth] => 0 [left] => 1 [right] => 18 )
EDIT: In regards to the update of the question.
Your input is a json_encoded array. simply json_decode it and you're done.
json_decode( $value, true );