3v4l.org

run code in 300+ PHP versions simultaneously

@ 2015-04-23T07:44:06Z

<?php

function findMyThing($needle, $haystack)
    {
        // We need to set up a stack array + a while loop to avoid recursive functions for those are evil.
        // Recursive functions would also complicate things further in regard of returning.
        $stack =
        [
            [
                'prefix' => [],
                'value' => $haystack
            ]
        ];
        // As long as there's still something there, don't stop
        while(count($stack) > 0)
        {
            // Copy the current stack and create a new, empty one
            $currentStack = $stack;
            $stack = [];
            // Work the stack
            for($i = 0; $i < count($currentStack); $i++)
            {
                // Iterate over the actual array
                foreach($currentStack[$i]['value'] as $key => $value)
                {
                    // If the value is an array, then
                    //   1. the key is a string (so we need to match against it)
                    //   2. we might have to go deeper
                    if(is_array($value))
                    {
                        // We need to build the current prefix list regardless of what we're gonna do below
                        $prefix = $currentStack[$i]['prefix'];
                        $prefix[] = $key;
                        // If the current key, is the one we're looking for, heureka!
                        if($key == $needle)
                        {
                            return $prefix;
                        }
                        // Otherwise, push prefix & value onto the stack for the next loop to pick up
                        else
                        {
                            $stack[] =
                            [
                                'prefix' => $prefix,
                                'value' => $value
                            ];
                        }
                    }
                    // If the value is NOT an array, then
                    //   1. the key is an integer, so we DO NOT want to match against it
                    //   2. we need to match against the value itself
                    elseif($value == $needle)
                    {
                        // This time append $value, not $key
                        $prefix = $currentStack[$i]['prefix'];
                        $prefix[] = $value;
                        return $prefix;
                    }
                }
            }
        }
        // At this point we searched the entire array and didn't find anything, so we return an empty array
        return [];
    }

$arr = [
        'USA' =>
        [
            'Alabama' =>
            [
                'Montgomery',
                'Birmingham'
            ],
            'Arizona' =>
            [
                'Phoenix',
                'Mesa',
                'Gilbert'
            ]
        ],
        'Germany' =>
        [
            'West Germany' =>
            [
                'Bonn',
                'Cologne'
            ]
        ]
    ];
    
var_dump(findMyThing('Alabama', $arr));
var_dump(findMyThing('Cologne', $arr));

Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6: array(2) { [0]=> string(3) "USA" [1]=> string(7) "Alabama" } array(3) { [0]=> string(7) "Germany" [1]=> string(12) "West Germany" [2]=> string(7) "Cologne" }
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29: Parse error: syntax error, unexpected '[' in /in/JY90G on line 8
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5: Parse error: parse error, unexpected '[' in /in/JY90G on line 8
Process exited with code 255.
Output for 4.3.2 - 4.3.4: Parse error: parse error in /in/JY90G on line 8
Process exited with code 255.

preferences:dark modelive preview

264.86 ms | 401 KiB | 456 Q