从索引列表中获取多维数组的值（数组也是如此）

I'm looking for a nice way of doing the magicFunction():

$indexes = array(1, 3, 0);

$multiDimensionalArray = array(
  '0',
  array('1-0','1-1','1-2',array('2-0','2-1','2-2')),
  array('1-4','1-5','1-6')
);

$result = magicFunction($indexes, $multiDimensionalArray);

// $result == '2-0', like if we did $result = $multiDimensionalArray[1][3][0];

Thanks.

My own attempt ; found it simpler by not doing it recursively, finally.

function magicFunction($arrayIndexes, $arrayData)
{
    if (!is_array($arrayData))
        throw new Exception("Parameter 'arrayData' should be an array");

    if (!is_array($arrayIndexes))
        throw new Exception("Parameter 'arrayIndexes' should be an array");

    foreach($arrayIndexes as $index)
    {
        if (!isset($arrayData[$index]))
            throw new Exception("Could not find value in multidimensional array with indexes '".implode(', ', $arrayIndexes)."'");

        $arrayData = $arrayData[$index];
    }

    return $arrayData;
}

Exceptions may be somewhat "violent" here, but at least you can know exactly what's going on when necessary.

Maybe, for sensitive hearts, a third $defaultValue optional parameter could allow to provide a fallback value if one of the indexes isn't found.

I think something like this should do the trick for you.

function magicFuntion($indexes, $marray)
{
    if(!is_array($indexes) || count($indexes) == 0 || !is_array($marray))
        return FALSE;

    $val = '';
    $tmp_arr = $marray;
    foreach($i in $indexes) {
        if(!is_int($i) || !is_array($tmp_arr))
            return FALSE;
        $val = $tmp_arr[$i];
        $tmp_arr = $tmp_arr[$i];
    }

    return $val;
}

You can solve this recursively.

$indexes = array(1, 3, 0);

$multiDimensionalArray = array(
  '0',
  array('1-0','1-1','1-2',array('2-0','2-1','2-2')),
  array('1-4','1-5','1-6')
);

$result = magicFunction($indexes, $multiDimensionalArray);

function magicFunction($indices, $array) {
        // Only a single index is left
        if(count($indices) == 1) {
                return $array[$indices[0]];
        } else if(is_array($indices)) {
                $index = array_shift($indices);
                return magicFunction($indices, $array[$index]);
        } else {
                return false; // error
        }
}

print $result;

This function will go down the $multiDimensionalArray as long as there are indices available and then return the last value accesses by the index. You will need to add some error handling though, e.g. what happens if you call the function with $indexes = array(1,2,3,4);?

Try this :P

function magicFunction ($indexes,$mdArr){
    if(is_array($mdArr[$indexes[0]] && $indexes)){
        magicFunction (array_slice($indexes,1),$mdArr[$indexes[0]]);
    }
    else {
        return  $mdArr[$indexes[0]];
    }
}

This is a recursive version. Will return null if it cannot find a value with the given index route.

function magicFunction($indexes, $array) {
    if (count($indexes) == 1) {
        return isset($array[$indexes[0]]) ? $array[$indexes[0]] : null;
    } else {
        $index=array_shift($indexes);
        return isset($array[$index]) ? magicFunction($indexes, $array[$index]) : null;
    }
}

You can just step trough based on your keys (no need to do any recursion, just a simple foreach):

$result = &$multiDimensionalArray;
foreach($indexes as $index)
{
    if (!isset($result[$index]))
        break; # Undefined index error

    $result = &$result[$index];
}

If you put it inside a function, then it won't keep the reference if you don't want to. Demo.