php/app/utils/ArrayUtil.php

<?php

namespace app\utils;

class ArrayUtil
{
    /**
     * 将数组内的 keys下划线转驼峰
     *
     * @param array $arr
     * @param string $separator
     *
     * @return array
     */
    public static function underline2CamelArr(array $arr, string $separator = '_'): array
    {
        $result = [];
        if (!empty($arr)) {
            foreach ($arr as $words => $value) {
                if (strpos($words, $separator) !== false) {
                    $words = $separator . str_replace($separator, " ", strtolower($words));
                    $result[ltrim(str_replace(" ", "", ucwords($words)), $separator)] = $value;
                } else {
                    $result[$words] = $value;
                }
            }
        }
        return $result;
    }
}