Question

我的大部分状态都想将其推送到数组中

我想将所有状态都推到除某些项目之外

这是我的状态

state = {
    username: '..',
    date: '..',
    time: '..',
    description: '..',
    images: '..',
    buildingNumber: '..',
    status: '..',
    serviceDB: '..',
    snapshotKey: '..', // i don't need this when pushed
    count: -1, // i don't need this when pushed
  };

这是我的代码

 let order = [];
    order.push(this.state);
    console.log(order); it's log all state 

// I want to push it to DB
    database()
      .ref(`Providers/ProvidersOrders/${uid}`)
      .push(...order);
  };

Answer 1

如果不使用任何库就可以使用destructuring assignment和rest parameters syntax：

const { snapshotKey, count, ...rest } = this.state;

...

order.push(rest);

否则，您也可以使用Lodash的_.omit函数：

order.push(_.omit(this.state, ['snapshotKey', 'count']));

或者，如果要选择要使用的属性，则可以再次使用解构和shorthand property names创建对象：

const {
    username,
    date,
    time,
    description,
    images,
    buildingNumber,
    status,
    serviceDB,
} = this.state;

...

order.push({
    username,
    date,
    time,
    description,
    images,
    buildingNumber,
    status,
    serviceDB,
});

或者与Lodash一起使用_.pick，与_.omit相反：

order.push(_.pick(this.state, [
    'username',
    'date',
    'time',
    'description',
    'buildingNumber',
    'status',
    'serviceDB',
]));

Answer 2

如果要选择一些属性，则只需声明所需的属性即可：

let {snapshotKey, count, ...y} = state;
arr.push(y);

一个例子：

state = {
    username: '1',
    date: '2',
    time: '3',
    description: '4',
    images: '5',
    buildingNumber: '6',
    status: '7',
    serviceDB: '8',
    snapshotKey: '9', // i don't need this when pushed
    count: -10, // i don't need this when pushed
  };
let arr = [];
let {snapshotKey, count, ...y} = state;
arr.push(y);
console.log(arr);

Answer 3

您可以使用解构分配如图所示 documentation

const {  count,snapshotKey, ...newData } = this.state;

现在，newData包含：

 newData={
    username: '..',
    date: '..',
    time: '..',
    description: '..',
    images: '..',
    buildingNumber: '..',
    status: '..',
    serviceDB: '..',
  };

现在在newData中使用

 database()
      .ref(`Providers/ProvidersOrders/${uid}`)
      .push(...newData);

您可以详细了解here and here also here 加上很棒的例子

如何将状态推送到包含特定项目的数组？

3 个答案: