Reactjs 在这段代码中，如果协调失败，那么它应该在if块之后返回station，但是我得到的是空白页，有人能帮我吗

如果代码中有输入错误，请在对象声明中将“使用”更改为“用户”：

const use={firstName : 'vineeth',lastName : 'Reddy'};   
function display(use)
{   
    return use.firstName+"  "+use.lastName;  
}  
function welcome(user)
{  
    if(user)
    {  
       return <p>welcome {display(user)}</p>;
    }
    return    <h1>welcome stranger{display(use)}</h1>;
}
ReactDOM.render(welcome(user),document.getElementById('root'));

在解释您的代码时，我想指出我猜您试图实现的目标

const user = { firstName: 'vineeth', lastName: 'Reddy' };

如果我错了，请告诉我

请回答您的问题，以便标题包含摘要，问题本身在正文中？欢迎陌生人{displayuse}；您希望传递用户不用于显示

import React from 'react';
import ReactDOM from 'react-dom';

const user = { firstName: 'vineeth', lastName: 'Reddy' };

function display(user) {
    return user.firstName + ' ' + user.lastName;
}

function welcome(user) {
    if (user) {
        return <p>welcome {display(user)}</p>;
    }
    // in case you don't get an user object in the args, probably you want to use a default user to say hello
    // const stranger = { firstName: 'name?', lastName: 'lastname?' };
    // return <h1>welcome stranger {display(stranger)}</h1>;

    // but I think would be clearer just: greetings mr. stranger
    return <h1>welcome stranger</h1>;
}

ReactDOM.render(welcome(user), document.getElementById('root1')); // -> welcome vineeth Reddy
ReactDOM.render(welcome(null), document.getElementById('root2')); // -> welcome stranger