Dynamically access deep values in a multidimensional array using an array of keys

Question

I want to check if an array key exists within an array.

I need to check up to 10 array keys.

When using array_key_exists I have to check each array key individually like so...

if (array_key_exists('key', $arr) and array_key_exists('key', $arr)) {}

I need to run that array key check up to ten times using and to append each array key check.

I searched online for a way to check multiple array keys at once to consolidate and keep neet this code. Then I found that array_key_exists is slower in performance than isset and empty.

Ref: How to check if multiple array keys exists

So my question(s) are:

Is speed an issue at this point when using array_key_exists to check for 10 keys within an array in one operation/function?
Is there a better way to do this?

array_key_exists is the only method I found that won't leave an undefined index error if that key doesn't exist.

Below is my code where I started using array_key_exists and the rest of the code not using array_key_exists is how I normally have this function routine.

// @Note
//  Let's discover how many indexes we need to apply to our this method variable

// If our index variable $key => $index[0] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

if (!isset($index[0])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method;

}

// If our index variable $key => $index[1] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[1])) {

    // ---
    // HERE I AM STARTING TO WRAP MY VARIABLE TO BE RETURNED IN ARRAY_KEY_EXISTS
    // ---

    // If our index array key exists within our this method array

    if (array_key_exists($index[0], $this_method)) {

        // Set our this method type and index count variable

        $this_method_type_and_index_count = $this_method [$index[0]];

    }

}

// If our index variable $key => $index[2] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[2])) {

    // ---
    // HERE I AM STARTING TO WRAP MY VARIABLE TO BE RETURNED IN ARRAY_KEY_EXISTS
    // ---

    // If our index array key exists within our this method array

    if (array_key_exists($index[0], $this_method) and array_key_exists($index[0], $this_method)) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]];

}

// ---
// BELOW IS HOW I HAVE THIS ROUTINE PRIOR TO ARRAY_KEY_EXISTS
// ---

// If our index variable $key => $index[3] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[3])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]];

}

// If our index variable $key => $index[4] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[4])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]];

}

// If our index variable $key => $index[5] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[5])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]];

}

// If our index variable $key => $index[6] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[6])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]] [$index[5]];

}

// If our index variable $key => $index[7] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[7])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]] [$index[5]] [$index[6]];

}

// If our index variable $key => $index[8] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[8])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]] [$index[5]] [$index[6]] [$index[7]];

}

// If our index variable $key => $index[9] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[9])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]] [$index[5]] [$index[6]] [$index[7]] [$index[8]];

}

// If our index variable $key => $index[10] is not set
// @Note
//  This means we have no further indexes to look for so let's stop now and set our this option variable

elseif (!isset($index[10])) {

    // Set our this method type and index count variable

    $this_method_type_and_index_count = $this_method [$index[0]] [$index[1]] [$index[2]] [$index[3]] [$index[4]] [$index[5]] [$index[6]] [$index[7]] [$index[8]] [$index[9]];

}

// Let's return our method type and index count variable

return $this_method_type_and_index_count;

[array_intersect_key()](http://php.net/manual/en/function.array-intersect-key.php) — Mark Baker, Feb 07 '17 at 15:05
your code seems really strange and repetitive, you should try and clean it a little, maybe use camelCase (using_the_under_scroll_is_so_old_and_annoying). — M. I., Feb 07 '17 at 15:18
also what is $this_method ? is it an a multi-array structure that has 7 subarrays ? — M. I., Feb 07 '17 at 15:21
Thanks about array_interect. I will check it out. Thank you. About the underscores, I will only simplify it when I see fit, which for now I don't see it applying. I'm writing my code for devs as well and when you read my code it sounds self-explanatory, read out loud. I want to stay along that line for now. This is part of an API for devs I am working on and I plan on them reading the code and I don't want to leave room for questions. But it will always be considered to simplify as time goes on and I can see fit. — Fearless Mode, Feb 07 '17 at 15:56

score 0 · Answer 1 · answered May 16 '23 at 20:59

Consolidate all of that repetitious, script-bloat condition block into a simple, breakable loop. Return as much of the source array data as the array of keys qualifies for.

Code: (Demo)

$this_method = ['foo' => ['bar' => ['bard' => ['food' => 'barf']]]];

$indexes = ['foo', 'bar', 'bard'];

function getBySuccessiveKeys(array $haystack, array $keys)
{
    foreach ($keys as $key) {
        if (!key_exists($key, $haystack)) {
            break;
        }
        $haystack = $haystack[$key];
    }
    return $haystack; 
}
var_export(getBySuccessiveKeys($this_method, $indexes));

Output:

array (
  'food' => 'barf',
)

Dynamically access deep values in a multidimensional array using an array of keys

1 Answers1