如何检查获取变量是否有数据

Question

function Login() {
const [email, setEmail] = useState("");
const [password, setpassword] = useState("");
const [users, setUser] = useState([]);
function login() {
fetch(
"http://116.202.231.219:8069/Restaurant/Login_Updated?Cont4=" +
email +
"&Pswd=" +
password
).then((result) => {
result.json().then((resp) => {
// console.warn(resp)
setUser(resp);
console.log(resp);
});
});
}
return (
<div className="col-sm-6 offset-sm-3">
<h1>Login Page</h1>
<br />
<input
type="text"
className="form-control"
onChange={(e) => setEmail(e.target.value)}
/>
<br />
<br />
<input
type="password"
className="form-control"
onChange={(e) => setpassword(e.target.value)}
/>
<br />
<br />
<button onClick={login} className="btn btn-primary">
Login
</button>
</div>
);
}

现在我想检查被获取的数据是否与输入的数据相同所以我尝试使用" if "而是"回应";变量不是全局的，我的意思是它不能和if一起工作。你们能帮我检查一下Email pass是否等于API中的Email pass吗

正如你所看到的，API正在获取cont4并从输入标签传递并返回对象但我无法在这个API上运行成功检查如果它返回对象则转到仪表板否则抛出错误警报

Answer 1

import axios from 'axios';
//add axios in your project
function Login() {
const [email, setEmail] = useState("");
const [password, setpassword] = useState("");
const [users, setUser] = useState({});

loginHandel = () => {
const url = `http://116.202.231.219:8069/Restaurant/Login_Updated?Cont4=${email}&Pswd=${password}`
axios.get(url).then((res) => {
//check the res if its getting the correct data or not?
//restructure accordingly
console.log(res);
const persons = res;
if ((persons?.email === email) && (persons?.password === password)) {
//perform any thing here
setUser(persons);
} else {
console.log("User email and passwoed mismatched!")
}
}).catch(err => {
//handel your error
console.log(err);
})
}
return (
<div className="col-sm-6 offset-sm-3">
<h1>Login Page</h1>
<br />
<form>

</form>
<input
type="text"
className="form-control"
onChange={(e) => setEmail(e.target.value)}
/>
<br />
<br />
<input
type="password"
className="form-control"
onChange={(e) => setpassword(e.target.value)}
/>
<br />
<br />
<button onClick={loginHandel} className="btn btn-primary">
Login
</button>
</div>
);
}