如何在ReactJS挂钩中映射数据？

如何解决如何在ReactJS挂钩中映射数据？

我想通过API收集JSON数据并将其呈现为JSX来显示，但是我是新来反应钩子的人，我看到一个错误，说data.map不是一个函数 有人可以帮我吗？

这是我的代码

import React,{useState,useEffect} from "react";
import axios from "axios";
import ModalSubHeader from "../../styles/ModalSubHeader";
import CollectionHolder from "../../styles/CollectionHolder";
import {Collectionoption,CollectionoptionInner} from "../../styles/Collectionoption";
import CollectionIcon from "../../styles/CollectionIcon";
import CollectionIcons from "../../../../images/index";

function Collection(props) {

const [collectionList,setCollectionList] = useState(null);
useEffect(() => {
    axios
    .get("https://reg.my-waste.mobi/collections?project_id=556&district_id=556&zone_id=zone-z1250-z1261")
    .then(({data}) => {
        data = data.collection.types;
        const collections = data.map((number) =>
            <Collectionoption>
                <CollectionoptionInner>
                    <CollectionIcon src={CollectionIcons[number.iconicShape]} />
                    {number.title}
                </CollectionoptionInner>
            </Collectionoption>
        );

        setCollectionList(collections)
    })        

    
    console.log(CollectionIcons);
})

return(
    <div>
        <ModalSubHeader>What type of collection or event would you like to be reminded about?</ModalSubHeader>
        <CollectionHolder>
            {collectionList}
        </CollectionHolder>
    </div>
)
}

export default Collection;

解决方法

此端点返回的对象不是数组，因此您应该对其进行一些修改Object.values（data.collection.types）.map（collection => {....}）

,

此代码可能有效：

import React,{useState,useEffect} from "react";
import axios from "axios";
import ModalSubHeader from "../../styles/ModalSubHeader";
import CollectionHolder from "../../styles/CollectionHolder";
import {CollectionOption,CollectionOptionInner} from "../../styles/CollectionOption";
import CollectionIcon from "../../styles/CollectionIcon";
import CollectionIcons from "../../../../images/index";

function Collection(props) {

const [collectionList,setCollectionList] = useState(null);
    useEffect(() => {
    axios
    .get("https://reg.my-waste.mobi/collections?    project_id=556&district_id=556&zone_id=zone-z1250-z1261")
    .then(({data}) => {
        data = data.collection.types;
        setCollectionList(Object.values(data).map(item=>        ({title:item.title,iconicShape:item.iconicShape})))
    })        


    console.log(CollectionIcons);
})

return(
    <div>
        <ModalSubHeader>What type of collection or event would you like to be reminded                                 
              about?</ModalSubHeader>
        <CollectionHolder>
            {collectionList.map((number) =>
            <CollectionOption>
                    <CollectionOptionInner>
                    <CollectionIcon src={CollectionIcons[number.iconicShape]} />
                    {number.title}
                </CollectionOptionInner>
            </CollectionOption>
        )}
        </CollectionHolder>
    </div>
)
}

export default Collection;