从带有angular6的对象中删除子对象

Question

有一个API会返回这样的数据

[

  {

    "id": 9,

    "name": "Past Menu",

    "serveDate": "2019-05-08 00:00:00",

    "meals": [

      {

        "id": 27,

        "name": "6",

        "description": "6",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 6,

        "status": "ENABLED"

      },

      {

        "id": 28,

        "name": "7",

        "description": "7",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 7,

        "status": "ENABLED"

      },

      {

        "id": 30,

        "name": "9",

        "description": "9",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 9,

        "status": "ENABLED"

      }

    ]

  },

  {

    "id": 8,

    "name": "Bomb Menu",

    "serveDate": "2019-05-10 00:00:00",

    "meals": [

      {

        "id": 28,

        "name": "7",

        "description": "7",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 7,

        "status": "ENABLED"

      },

      {

        "id": 30,

        "name": "9",

        "description": "9",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 9,

        "status": "ENABLED"

      },

      {

        "id": 31,

        "name": "10",

        "description": "10",

        "image": "",

        "mealType": "BREAKFAST",

        "unitPrice": 10,

        "status": "ENABLED"

      }

    ]

  }

]

服务

getMenus() {

  this.dataServices.menuList(this.pagedData)

  .subscribe(

    response => {

      if (response && response.code === HttpStatus.OK) {

        this.dataList = response.data;

      }

    },

  );

}

我目前正在尝试做的是能够从服务器返回的数据中删除子对象，因此我具有此功能

deleteItem(item) {

  for (let r = 0; r < this.dataList.meals.length; r++) {

    if (this.dataList.meals[r].id === item.id) {

    this.dataList.meals.splice(r, 1);

    }

  }

}

当我调用该函数时，出现此错误 ERROR TypeError: Cannot read property 'length' of undefined