Using vue watch listening objects, how do I get the properties that are currently changing?

A question, such as a question, is not a value of the listening object, but an attempt to obtain the attribute that has changed

.

the environmental background of the problems and what methods you have tried

the following way of writing has been tried to listen for more object properties, so the mind is greatly inspired to wonder whether it is possible to listen for current changes and deal with them directly
"rooms.a.b" (oldval,newval) {

.
   .... 

}

"rooms.a.c" (oldval,newval) {

   .... 

}

"rooms.b.a" (oldval,newval) {

   .... 

}

related codes

rooms: {

    handler(val) {
      
      this.scrollDown();
      if (!this.currentRoom) return;
     

      try {
        sessionStorage.setItem(this.currentRoom, JSON.stringify(content));
      } catch (oException) {
        if (oException.name === "QuotaExceededError") {
          layer.msg(",!");

          //
          sessionStorage.removeItem(this.currentRoom);
          this.rooms[this.currentRoom].historyContent = [];
        }
      }
    },
    deep: true
  },

what result do you expect? What is the error message actually seen?

because there are many attributes of objects that need to be listened to, is it feasible to listen to objects directly and get the attributes that have changed currently?

Mar.26,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e6463a-45a96.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e6463a-45a96.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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