我为此花了一整天的时间,在谷歌上搜索并寻找答案,但仍然无法弄清楚。
我的代码有点长,它在 Firefox 中运行良好,但从 Chrome 获取“Uncaught SyntaxError: Unexpected token u”。
谁能指出我错在哪里?提前致谢!
// when the page loads, list all the current contacts
$(document).ready(function(){
// check if localStorage database exists
if(!localStorage.getItem("customerDatabase")){
// define a JSON object to hold all current address
var contacts = {
"users":[
{
"id":"1",
"name":"dennis",
"email":"dennisboys@gmail.com"
},
{
"id":"2",
"name":"zoe",
"email":"zoeisfemale@gmail.com"
}
]
} // end of contacts JSON object
// stringify the object
var stringObject = JSON.stringify(contacts);
// store it into localStorage database
var storedDatabase = localStorage.setItem("customerDatabase", stringObject);
} else {
// list all customers upon page loads
listJSONCustomers();
}
// list all current contacts from JSON object in localStorage
function listJSONCustomers(){
var displayHTML = "";
var i;
// get the data from localStorage
var storedDatabase = localStorage.getItem("customerDatabase");
// parse the data from string to JSON object
var parseObject = JSON.parse(storedDatabase);
// access the users key of the JSON object
var userObject = parseObject.users;
// get the length of the object (how many customers the database has)
var contactsLength = userObject.length;
for(i=0; i<contactsLength; i++){
var trElement = '<tr id="address' + (i+1) + '">';
var tdId = '<td id="id' + (i+1) + '">' + userObject[i].id + '</td>';
var tdName = '<td id="name' + (i+1) + '">' + userObject[i].name + '</td>';
var tdEmail = '<td id="email' + (i+1) + '">' + userObject[i].email + '</td>';
var tdButton = '<td id="button"><button id="editButton' + userObject[i].id + '">Edit</button> | <button id="deleteButton' + userObject[i].id + '">Delete</button></td>';
displayHTML += trElement + tdId + tdName + tdEmail + tdButton + '</tr>';
}
$('#address_list').html(displayHTML);
}
// add customer to database
$('#saveCustomer').click(function(){
if( $('#customerName').val() !== "" && $('#customerEmail').val() !== "" ){
var customerName = $('#customerName').val();
var customerEmail = $('#customerEmail').val();
// get the data from localStorage
var storedDatabase = localStorage.getItem("customerDatabase");
// parse the data from string to JSON object
var parseObject = JSON.parse(storedDatabase);
// access the users key of the JSON object
var userObject = parseObject.users;
// get the new entry
var newCustomerObject = {
"id": userObject.length + 1,
"name": customerName,
"email": customerEmail
};
// push the new entry into the object
userObject.push(newCustomerObject);
// convert the object into string for localStorage
var stringObject = JSON.stringify(parseObject);
// store the JSON object into localStorage
var storedDatabase = localStorage.setItem("customerDatabase", stringObject);
// list all customes again every time a database receives a new entry
listJSONCustomers();
} else {
alert("Please enter customer's name and email.");
}
}); // end of $('#saveCustomer').click();
});
最佳答案
在某些时候,您所做的某些事情损坏了该键的 LocalStorage 值。 LocalStorage 只能存储字符串,因此如果您向它传递任何其他内容,它会将其转换为字符串。由于您的值为 'undefined'
,这意味着在某些时候,您可能不小心做了这样的事情:
var value;
localStorage.setItem('key', value);
在这种情况下,value
是undefined
,它不是字符串。保存后,它将被转换。不幸的是,"undefined"
不是有效的 JSON。这意味着当它尝试解析时,它会抛出异常。
要解决您的问题,您应该使用 removeItem
清除错误值。
localStorage.removeItem("customerDatabase");
关于javascript - 为什么我总是从 Chrome 获得 "Uncaught SyntaxError: Unexpected token u "?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14681366/