Accessing PHP associative array with index represented as string - php

Question

Is it possible to do something like this in PHP?
$index1 = "[0][1][2]";
$index2 = "['cat']['cow']['dog']";
// I want this to be $myArray[0][1][2]
$myArray{$index1} = 'stuff';
// I want this to be $myArray['cat']['cow']['dog']
$myArray{$index2} = 'morestuff';
I've searched for a solution, but I don't think I know the keywords involved in figuring this out.

Answer 1

eval('$myArray[0][1][2] = "stuff";');
eval('$myArray'.$index1.' = "stuff";');
But be careful when using eval and user input as it is vulnerable to code injection attacks.

Answer 2

Not directly. $myArray[$index] would evaluate to $myArray['[0][1][2]']. You would probably have to separate each dimension or write a little function to interpret the string:
function strIndexArray($arr, $indices, $offset = 0) {
$lb = strpos($indices, '[', $offset);
if ($lb === -1) {
return $arr[$indices];
}
else {
$rb = strpos($indices,']', $lb);
$index = substr($indices, $lb, $rb - $lb);
return strIndexArray($arr[$index], substr($indices, $rb+1));
}
}
You can probably find some regular expression to more easily extract the indices which would lead to something like:
$indices = /*regex*/;
$value = '';
foreach($indices as $index) {
$value = $array[$index];
}
To set a value in the array the following function could be used:
function setValue(&$arr, $indices, $value) {
$lb = strpos($indices, '[');
if ($lb === -1) {
$arr = $value;
}
else {
$rb = strpos($indices, ']', $lb);
$index = substr($indices, $lb, $rb);
setValue($arr[$index], substr($indices, $lb, $rb+1), $value);
}
}
Note: I made above code in the answer editor so it may contain a typo or two ; )

Answer 3

$index1 = "[0][1][2]";
$index2 = "['cat']['cow']['dog']";
function myArrayFunc(&$myArray,$myIndex,$myData) {
$myIndex = explode('][',trim($myIndex,'[]'));
$m = &$myArray;
foreach($myIndex as $myNode) {
$myNode = trim($myNode,"'");
$m[$myNode] = NULL;
$m = &$m[$myNode];
}
$m = $myData;
}
// I want this to be $myArray[0][1][2]
myArrayFunc($myArray,$index1,'stuff');
// I want this to be $myArray['cat']['cow']['dog']
myArrayFunc($myArray,$index2,'morestuff');
var_dump($myArray);

Answer 4

There's always the evil eval:
eval('$myArray' . $index1 . ' = "stuff";');

Answer 5

You can use two anonymous functions for this.
$getThatValue = function($array){ return $array[0][1][2]; };
$setThatValue = function(&$array, $val){ $array[0][1][2] = $val; };
$setThatValue($myArray, 'whatever');
$myValue = $getThatValue($myArray);