Question

现在，我的API中有一个类似于以下内容的对象-

design: {
    "_id": "5b291367e3d1390d86931b44",
    "name": "PRP15",
    "thickness1": {
      "name": "4/4",
      "price": 12.64
    },
    "thickness2": {
      "name": "5/4",
      "price": 14.99
    },
    "createdAt": "2018-06-19T14:29:59.930Z",
    "updatedAt": "2018-07-22T01:30:16.316Z",
    "__v": 0,
    "photo": null,
}

当我控制台登录 design.thickness1 我要返回

{name: "4/4", price: 12.64}

但是，当我执行 design.thickness1.price 它返回时

undefined

如果我执行 design.thickness2.price

，它也会这样做

我不知道为什么，而且即时通讯似乎无济于事。任何帮助将非常感激！我什至尝试用相同的对象创建变量，并且确实返回正确的值

编辑：这是我目前的使用方式

const { design } = this.props

console.log('Design:   ' + JSON.stringify(design, null, 2)); 
//returning
//{
  //"_id": "5b291367e3d1390d86931b44",
  //"name": "PRP15",
  //"thickness1": {
    //"name": "4/4",
    //"price": 12.64
  //},
  //"thickness2": {
    //"name": "5/4",
   //"price": 14.99
  //},
  //"createdAt": "2018-06-19T14:29:59.930Z",
  //"updatedAt": "2018-07-22T01:30:16.316Z",
  //"__v": 0,
  //"photo": null,
//}


console.log('Thickness1 Price:   ' + JSON.stringify(design.thickness1, null, 2));
//returning {name: "4/4", price: 12.64}

console.log('Design Price:   ' + JSON.stringify(design.thickness1.price, null, 2));
//returning undefined



const mapStateToProps = (state) => ({
  design: state.part_list.designs
});


export default connect(mapStateToProps, mapDispatchToProps)(DoorOrders);

Answer 1

固定

基本上反应是试图在它具有值之前将其渲染并崩溃，因此我添加了条件

if(!designs[0].thickness1){
  return null
}else{
  console.log('Design Price:   ' + (JSON.stringify(designs[0].thickness1.price)));
  console.log(typeof (designs[0].thickness1.price));
}

对象返回值未定义

1 个答案: