react-study/src/components/Pub.js

import React, {Component} from 'react';
import PubSub from 'pubsub-js'
import Axios from "axios";
class Pub extends Component {
    constructor(props, context) {
        super(props, context);
        this.state = {
            dataList: []
        }
        PubSub.subscribe('vtt',(msg,data)=>{
            console.log(data)
        })
    }
    componentDidMount() {
        Axios.get("http://localhost:4000/arr").then((res)=>{
            this.setState({
                dataList: res.data
            })
        })
    }

    render() {
        return (
            <div>
                {this.state.dataList.map((v,k)=>{
                    return <p key={k}>{v.name}</p>
                })}
            </div>
        );
    }
}
export default Pub;