如何从Firebase中的用户获取名字和姓氏？

// 初始化Firebase
const firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "YOUR_AUTH_DOMAIN",
  projectId: "YOUR_PROJECT_ID",
  storageBucket: "YOUR_STORAGE_BUCKET",
  messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
  appId: "YOUR_APP_ID"
};

firebase.initializeApp(firebaseConfig);

// 获取当前登录用户
firebase.auth().onAuthStateChanged(user => {
  if (user) {
    // 用户已登录
    const displayName = user.displayName;
    const firstName = displayName.split(' ')[0];
    const lastName = displayName.split(' ').slice(-1)[0];

    console.log("First Name:", firstName);
    console.log("Last Name:", lastName);
  } else {
    // 用户未登录
    console.log("No user is signed in.");
  }
});

if (user && user.displayName) {
  const firstName = user.displayName.split(' ')[0];
  const lastName = user.displayName.split(' ').slice(-1)[0];
  console.log("First Name:", firstName);
  console.log("Last Name:", lastName);
} else {
  console.log("User display name is not set.");
}

const firstName = user.displayName.match(/^[^ ]+/)[0];
const lastName = user.displayName.match(/ [^ ]+$/)[0];