So here's the input:
$in['a--b--c--d'] = 'value';
And the desired output:
$out['a']['b']['c']['d'] = 'value';
Any ideas? I've tried the following code without any luck...
$in['a--b--c--d'] = 'value';
// $str = "a']['b']['c']['d";
$str = implode("']['", explode('--', key($in)));
${"out['$str']"} = 'value';
This seems like a prime candidate for recursion.
The basic approach goes something like:
The recursion below does precisely this, during each call a new array is created, the first key in the list is assigned as the key for a new value. During the next step, if there are keys left, the procedure repeats, but when no keys are left, we simply return the value.
$keys = explode('--', key($in));
function arr_to_keys($keys, $val){
if(count($keys) == 0){
return $val;
}
return array($keys[0] => arr_to_keys(array_slice($keys,1), $val));
}
$out = arr_to_keys($keys, $in[key($in)]);
For your example the code above would evaluate as something equivalent to this (but will work for the general case of any number of -- separated items):
$out = array($keys[0] => array($keys[1] => array($keys[2] => array($keys[3] => 'value'))));
Or in more definitive terms it constructs the following:
$out = array('a' => array('b' => array('c' => array('d' => 'value'))));
Which allows you to access each sub-array through the indexes you wanted.
eval, but I wouldn't recommend it. something like eval("\$out['a']['b']['c']['d'] = 'value';") would be equivalent.$temp = &$out = array();
$keys = explode('--', 'a--b--c--d');
foreach ($keys as $key) {
$temp[$key] = array();
$temp = &$temp[$key];
}
$temp = 'value';
echo $out['a']['b']['c']['d']; // this will print 'value'
In the code above I create an array for each key and use $temp to reference the last created array. When I run out of keys, I replace the last array with the actual value. Note that $temp is a REFERENCE to the last created, most nested array.
