I have a string that contains elements from array.
$str = '[some][string]';
$array = array();
How can I get the value of $array['some']['string'] using $str?
4 Answers
This will work for any number of keys:
$keys = explode('][', substr($str, 1, -1));
$value = $array;
foreach($keys as $key)
$value = $value[$key];
echo $value
4 Comments
Alex Emilov
Actually, this is the best case.I won't remove the accepted from @hakre, but I gave you+.Thanks to all that have participated!
Eric
@Daniel: Care to elaborate?
Daniel Gelling
@Eric No need for that :)
Eric
Gaah, @BobGregor edited it and broke it (replacing
$array with array()You can do so by using eval, don't know if your comfortable with it:
$array['some']['string'] = 'test';
$str = '[some][string]';
$code = sprintf('return $array%s;', str_replace(array('[',']'), array('[\'', '\']'), $str));
$value = eval($code);
echo $value; # test
However eval is not always the right tool because well, it shows most often that you have a design flaw when you need to use it.
Another example if you need to write access to the array item, you can do the following:
$array['some']['string'] = 'test';
$str = '[some][string]';
$path = explode('][', substr($str, 1, -1));
$value = &$array;
foreach($path as $segment)
{
$value = &$value[$segment];
}
echo $value;
$value = 'changed';
print_r($array);
This is actually the same principle as in Eric's answer but referencing the variable.
3 Comments
Eric
If he isn't comfortable with it, he shouldn't be storing the string that way.
hakre
@Eric: Don't know, but your solution looks much nicer :)
Alex Emilov
Its perfect.I've already tried with eval, but I didn't make it really well.
// trim the start and end brackets
$str = trim($str, '[]');
// explode the keys into an array
$keys = explode('][', $str);
// reference the array using the stored keys
$value = $array[$keys[0][$keys[1]];
2 Comments
Alex Emilov
Hi, what about bigger arrays? Anyway thanks for the response!
Adam Hopkinson
Bigger arrays weren't part of the original question!
I think regexp should do the trick better:
$array['some']['string'] = 'test';
$str = '[some][string]';
if (preg_match('/\[(?<key1>\w+)\]\[(?<key2>\w+)\]/', $str, $keys))
{
if (isset($array[$keys['key1']][$keys['key2']]))
echo $array[$keys['key1']][$keys['key2']]; // do what you need
}
But I would think twice before dealing with arrays your way :D
$array[$key1][$key2].