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.
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.
eval() the only solution?
eval might not be the only solution, but it is the best one. eval is exactly what you are looking for. Please don't mindlessly ignore the best solution just because you've heard people say "eval is evil".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), $value);
}
}
Note: I made above code in the answer editor so it may contain a typo or two ; )
'[a as index, then again, it uses that index both for getting and setting so all is not lost. Besides that, I've never in my life used a [ or ] in an array index, but I can understand that's just me.eval() could be an acceptable solution, but having a function call with the intent is much better in practice.$lb2 = strpos($indices,'[',$lb); $lb2 < $rb; could catch that special case.$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);
There's always the evil eval:
eval('$myArray' . $index1 . ' = "stuff";');
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);
"[0][1][2]" was variable.
$array['cow']into a function, I'm pretty sure you cannot access$arrayfrom that function (even if passed by reference)