PHP 数组辅助函数

/**
 * 取多维数据中某字段的值
 * @param  array         $array  数据源数组
 * @param  string|array  $field  要获取的字段
 * @return array                 结果数组
 */
function array_muliti_field($array, $field)
{
    $resp = [];
    foreach($array as $k => $v) {
        if(is_array($field)) {
            foreach($field as $f) {
                if(isset($v[$f]) && $v[$f] !== null) {
                    $resp[$f][$v[$f]] = $v[$f];
                }
            }
        } elseif(isset($v[$field]) && $v[$field] !== null){
            $resp[] = $v[$field];
        }
    }
    return $resp;
}/**
 * 将多维数组中的某一个元素作为键名，重新生成数组
 *
 * $array = [
 *     0 => ['id'=>10, 'title'=>'t10'],
 *     1 => ['id'=>11, 'title'=>'t11']
 * ];
 *
 * $res = array_set_key($array, 'id');
 *
 * 结果如下:
 * $res = [
 *     10 => ['id'=>10, 'title'=>'t10'],
 *     11 => ['id'=>11, 'title'=>'t11']
 * ];
 *
 * @param  array   $array    要处理的数组
 * @param  string  $key      作为 key 的字段名称
 * @param  string  $valuekey [description]
 * @return array             新生成的数组
 */
function array_set_key($array, $key = '', $valuekey = '')
{
    $res = [];
    while (list($k, $v) = each($array)) {
        if ($key == '') {
            $res[] = (($valuekey != '') ? $v[$valuekey] : $v);
        } else {
            $res[$v[$key]] = (($valuekey != '') ? $v[$valuekey] : $v);
        }
    }
    reset($array);
    return $res;
}/**
 * 将多维数组中的某两个元素作为键名组成二维数组
 * $array = [
 *     0 => ['id'=>10,'title'=>'t10'],
 *     1 => ['id'=>11,'title'=>'t11'],
 *     2 => ['id'=>11,'title'=>'t12']
 * ];
 *
 * $res = array_set_keys($array, 'id', 'title');
 *
 * 结果如下:
 * $res = [
 *     10 => [
 *         't10' => ['id'=>10,'title'=>'t10']
 *     ],
 *
 *     11 => [
 *         't11' => ['id'=>11,'title'=>'t11'],
 *         't12' => ['id'=>11,'title'=>'t12']
 *     ]
 * ];
 * @param  [type] $array    [description]
 * @param  [type] $key1     [description]
 * @param  string $key2     [description]
 * @param  string $valuekey [description]
 * @return [type]           [description]
 */
function array_set_keys($array, $key1, $key2 = '', $valuekey = '')
{
    $res = [];
    while (list($k, $v) = each($array)) {
        $k1 = $v[$key1];
        $vl = ($valuekey != '') ? $v[$valuekey] : $v;
        if ($key2 == '') {
            $res[$k1][] = $vl;
        } else {
            $res[$k1][$v[$key2]] = $vl;
        }
    }
    reset($array);
    return $res;
}