查找数组中上一个元素键/值，下一个元素键/值

find_key_value.php

<?php
    /*
     * 查找数组中上一个元素键/值，下一个元素键/值
     * @param   str     $currentValue   当前元素的值
     * @param   array   $array          待查询数组
     * @return  array   上一个元素键/值，下一个元素键/值
     */
    public function arrayPrevNext($currentValue, $array)
    {
        $prev_key = $next_key = null;
        $prev_value = $next_value = null;
        $findCurrentValue = false;

        foreach ($array as $key => $value) {
            if ($findCurrentValue) {
                $next_key = $key;
                $next_value = $value;
                break;
            }
            if ($value == $currentValue) {
                $findCurrentValue = true;
            } else {
                $prev_key = $key;
                $prev_value = $value;
            }
        }
        $result = [
            'prev_key' => $prev_key,
            'prev_value' => $prev_value,
            'next_key' => $next_key,
            'next_value' => $next_value,
        ];
        return $result;
    }