正则匹配引号中间的内容，匹配json的key，替换多维数组的key

正则表达式：

(?<=")[a-z_]+(?=":)

匹配示例：

{"api_token":"1,32|xxx","identity_token":"1,1598333646,xxx,2","user":{"nickname":"scsasdad","avatar":"111111","country_code":null,"telephone":"xxx","email":"","language":"zh","last_login_time":xxx,"status":20,"user_id":1,"user_profile":{"user_id":1,"first_name":"阳","last_name":"","gender":1,"birthday":"1990-09-19","company":"xx科技","industry":"计算机","position":"后端工程师","education":"本科","address":"xx花园","city":"武汉","postcode":"430000","country":"中国"}}}

我做这个的用途是，有时候不同的接口需要的返回格式不一致，有的需要返回snake键名，有时候需要camlCase键名。具体代码如下：

/**
 * 蛇形转camel
 * @author Bruce 2020-08-25
 *
 * @param  string $value          [description]
 * @return [type] [description]
 */
function snake_to_camel($value = '')
{
    $value = ucwords(str_replace(['-', '_'], ' ', $value));
    return lcfirst(str_replace(' ', '', $value));
}

/**
 * 多维数组的key变成camelCase
 * @author Bruce 2020-08-25
 *
 * @param  array  $result         [description]
 * @return [type] [description]
 */
function camel_result($result = [])
{
    $result = json_encode($result, 320);
    $new = preg_replace_callback('/(?<=")[a-z_]+(?=":)/', function ($matches) {
        return snake_to_camel($matches[0]);
    }, $result);
    return json_decode($new, true);
}

多维结果示例：