1<?php
2/**
3 * This file is part of the array_column library
4 *
5 * For the full copyright and license information, please view the LICENSE
6 * file that was distributed with this source code.
7 *
8 * @copyright Copyright (c) Ben Ramsey (http://benramsey.com)
9 * @license http://opensource.org/licenses/MIT MIT
10 */
11
12if (!function_exists('array_column')) {
13    /**
14     * Returns the values from a single column of the input array, identified by
15     * the $columnKey.
16     *
17     * Optionally, you may provide an $indexKey to index the values in the returned
18     * array by the values from the $indexKey column in the input array.
19     *
20     * @param array $input A multi-dimensional array (record set) from which to pull
21     *                     a column of values.
22     * @param mixed $columnKey The column of values to return. This value may be the
23     *                         integer key of the column you wish to retrieve, or it
24     *                         may be the string key name for an associative array.
25     * @param mixed $indexKey (Optional.) The column to use as the index/keys for
26     *                        the returned array. This value may be the integer key
27     *                        of the column, or it may be the string key name.
28     * @return array
29     */
30    function array_column($input = null, $columnKey = null, $indexKey = null)
31    {
32        // Using func_get_args() in order to check for proper number of
33        // parameters and trigger errors exactly as the built-in array_column()
34        // does in PHP 5.5.
35        $argc = func_num_args();
36        $params = func_get_args();
37
38        if ($argc < 2) {
39            trigger_error("array_column() expects at least 2 parameters, {$argc} given", E_USER_WARNING);
40            return null;
41        }
42
43        if (!is_array($params[0])) {
44            trigger_error(
45                'array_column() expects parameter 1 to be array, ' . gettype($params[0]) . ' given',
46                E_USER_WARNING
47            );
48            return null;
49        }
50
51        if (!is_int($params[1])
52            && !is_float($params[1])
53            && !is_string($params[1])
54            && $params[1] !== null
55            && !(is_object($params[1]) && method_exists($params[1], '__toString'))
56        ) {
57            trigger_error('array_column(): The column key should be either a string or an integer', E_USER_WARNING);
58            return false;
59        }
60
61        if (isset($params[2])
62            && !is_int($params[2])
63            && !is_float($params[2])
64            && !is_string($params[2])
65            && !(is_object($params[2]) && method_exists($params[2], '__toString'))
66        ) {
67            trigger_error('array_column(): The index key should be either a string or an integer', E_USER_WARNING);
68            return false;
69        }
70
71        $paramsInput = $params[0];
72        $paramsColumnKey = ($params[1] !== null) ? (string) $params[1] : null;
73
74        $paramsIndexKey = null;
75        if (isset($params[2])) {
76            if (is_float($params[2]) || is_int($params[2])) {
77                $paramsIndexKey = (int) $params[2];
78            } else {
79                $paramsIndexKey = (string) $params[2];
80            }
81        }
82
83        $resultArray = array();
84
85        foreach ($paramsInput as $row) {
86            $key = $value = null;
87            $keySet = $valueSet = false;
88
89            if ($paramsIndexKey !== null && array_key_exists($paramsIndexKey, $row)) {
90                $keySet = true;
91                $key = (string) $row[$paramsIndexKey];
92            }
93
94            if ($paramsColumnKey === null) {
95                $valueSet = true;
96                $value = $row;
97            } elseif (is_array($row) && array_key_exists($paramsColumnKey, $row)) {
98                $valueSet = true;
99                $value = $row[$paramsColumnKey];
100            }
101
102            if ($valueSet) {
103                if ($keySet) {
104                    $resultArray[$key] = $value;
105                } else {
106                    $resultArray[] = $value;
107                }
108            }
109
110        }
111
112        return $resultArray;
113    }
114
115}
116