phpcms切換到php7.2後沒法修改文章提示Uncaught Error: [] operator not supported for strings

　　前段時間將客戶的phpcms站點升級到php7.2，相對比較順利，可是今天他反應文章沒法修改了，提示Uncaught Error: [] operator not supported for strings 錯誤，這就有點尷尬了，多是PHP7以上對語法要求比較嚴謹，那咱們就照着錯誤提示來尋找解決方案

Fatal error: Uncaught Error: [] operator not supported for strings in 
*****\phpcms\modules\admin\classes\push_api.class.php:145 Stack trace: #0 
*****\phpcms\modules\admin\classes\push_api.class.php(50): push_api->position_list(Array, Array, 0, 'content_model') #1 
*****\caches\caches_model\caches_data\content_update.class.php(62): push_api->position_update(4, 1, 14, Array, Array, 0) #2 
*****\caches\caches_model\caches_data\content_update.class.php(18): content_update->posid('posids', Array) #3 
*****\phpcms\model\content_model.class.php(303): content_update->update(Array) #4 
*****\phpcms\modules\content\content.php(221): content_model->edit_content(Array, 4) #5 
*****\phpcms\libs\classes\application.class.php(31): content->edit() #6 
*****\phpcms\libs in 
*****\phpcms\modules\admin\classes\push_api.class.php on line 145

　　打開/phpcms/modules/admin/classes/push_api.class.php，大概在約 141行，

$fields_arr = $fields_value = '';

　　將它改成

$fields_arr = $fields_value = [];

　　保存，上傳，覆蓋文件，從新編輯一下文章看看，此次果真能夠了