在下面的代碼片段中，我從java Servlet接收一個JSON對象并訪問該對象的屬性。JSON 對象：{  "redirect": "/index.html",  "logout": "/_cloudshellProxy/_ah/logout?continue\u003d%2Findex.html",  "status": true,  "register": true,  "user": {    "email": "s@example.com",    "username": "Yevesky",    "college": {      "name": "Lafayette College",      "key": "aglzcHN0ZWFtMTlyFAsSB0NvbGxlZ2UYgICAgICAswgM"    },    "key": "aglzcHN0ZWFtMTlyEQsSBFVzZXIYgICAgICgxAgM"  }}以下是我如何處理來自 servlet 的對象。fetch("/getUserInfo").then(response => response.json()).then(object =>    {        jsonObject = object;        console.log(jsonObject);        setUpUserPage(jsonObject);        loadClasses();    });    function setUpUserPage(json){    const jsonData = json;    var name = document.createElement("h3");    name.innerText = String(jsonData.username);    var uni = document.createElement("h6");    uni.innerText = String(jsonData.college.name); // Error occurs here    var classification = document.createElement("h6");    console.log(jsonData.classes);        if (jsonData?.isProf)    {        classification.innerText = "Professor";    }    else    {        classification.innerText = "Student";    }    var email = document.createElement("h6");    email.innerText = String(jsonData.email);    var spacer = document.createElement("BR");    //change nickname link    var changeNicknameP = document.createElement("p");    changeNicknameP.innerText = "Change your nickname: ";    var anchor = document.createElement("A");    var link = document.createTextNode("here");    anchor.setAttribute("href", "#");    anchor.appendChild(link);    changeNicknameP.appendChild(anchor);}問題是我不明白為什么我會得到一個“TypeError：無法讀取未定義的屬性'名稱'”，如果對象有這樣的屬性？它只是JavaScript還是我沒有遵循一個過程。我每次都會在控制臺上打印JSON對象，以查看該屬性是否確實存在。