Select value from a multidimensional array using a delimited string?

[Adam]

Hey everyone! Bit stuck here. Not sure if I'm thinking about this too much or whether it's just insanely hard. Basically I want to return a value from a multidimensional array based off of a string with delimiters.

 

Probably easier to show you than to explain:

 

$str = 'str1.str2.str3';

$array = array(
    'str1' => array(
        'str2' => array(
            'str3' => 'I want to return this...',
        ),
    ),
);

 

So using $str I want to traverse through the array to return 'I want to return this...'

 

Any body have any ideas? I'm pretty stumped!

 

Thanks in advance,

Adam

[Catfish]

1. explode $str on period character .

2. use each str as a key reference from the array:

    print($array[$str1][$str2][$str3]);

[Adam]

Sorry. I should have mentioned I don't know how many levels the string will go into, should be unlimited.

[DavidAM]

something along these lines should work.  You just keep capturing a pointer to the element of interest until you have traversed the entire list of keys. 

$str = 'str1.str2.str3';

$array = array(
    'str1' => array(
        'str2' => array(
            'str3' => 'I want to return this...',
        ),
    ),
);

$keys = explode ($str, "."); // or is it explode(".", $str)?  I can never remember
$hold = &$array;
foreach ($keys as $key) {
  $hold = &$hold[$key];
}

// $hold now points to the field you are looking for

 

Watchout though.  If $str starts out as "str1.str2" you will end up with $hold referencing $array[str1][str2] which is an array NOT a string value.

 

[Adam]

Thanks for that DavidAM. I actually managed to solve it in a slightly different way using a recursive function:

 

    public function get($property)
    {
        $tokens = explode('.', $property);
        $return = $this->properties;

        foreach ($tokens as $token)
        {
            $return = $this->recurseGet($token, $return);

            if (!$return)
            {
                break;
            }
        }

        return $return;
    }

    protected function recurseGet($token, $properties)
    {
        if (array_key_exists($token, $properties))
        {
            return $properties[$token];
        }

        return false;
    }

 

Thanks anyway though, much appreciated!