我使用一个小应用程序，前端看起来如下所示，
选择货币后，Address Generate 按钮处于事件状态，单击它会打开一个带有输入选项的模式。
我想在全局上下文中使用钱包名称。着陆页的代码在这里，
<body id="page-top" class="index">
<!-- modal for providing the name of the wallet-->
<div id="walletNameModal" class="modal fade bd-example-modal-sm" role="dialog"
aria-labelledby="mySmallModalLabel" aria-hidden="true" tabindex="-1">
<div class="modal-dialog modal-sm" role="document">
<!--layout of the set of modals-->
<div class="modal-content">
<!--modal header-->
<div class="modal-header">
<!--close the dialog-->
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Wallet Name</h4>
</div>
<!--modal body-->
<div class="modal-body">
<!--provide the wallet name as input text-->
<input id="addressName" type="text" class="form-control">
</div>
<!--modal footer-->
<div class="modal-footer">
<button id="addressNameSubmitBtn" type="button" class="btn btn-default" data-dismiss="modal">Submit
</button>
</div>
</div>
</div>
</div>
<section id="myform">
<div class="container">
<div class="row">
<div class="col-lg-10">
<form name="landingBox" id="walletForm" class="form-inline" novalidate>
<!--Select Currency-->
<div class="form-group controls">
<select id="selectCurrency" name="" title="Select Currency"
class="btn-primary form-control">
<option selected disabled>Select Currency</option>
<option value="0">Bitcoin</option>
<option value="1">Ethereum</option>
<option value="2">Litecoin</option>
<option value="3">Nem</option>
<option value="4">Ripple</option>
<option value="5">Dash</option>
</select>
</div>
<!--Generate Address-->
<div class="form-group controls">
<button id="generateAddress" type="button" class="btn btn-primary" disabled>
Address Generate
</button>
</div>
<!--Show Balance-->
<div class="form-group controls">
<button id="balance" type="button" class="btn btn-primary" disabled>
Balance
</button>
</div>
<!--Show Transactions -->
<div class="form-group controls">
<button id="transactions" type="button" class="btn btn-primary" disabled>
Transactions
</button>
</div>
<!--Send Money-->
<div class="form-group controls">
<button id="sendMoney" type="button" class="btn btn-primary" disabled>
Transactions
</button>
</div>
</br>
</br>
<!--Select Address Drop-down-->
<div class="form-group controls">
<select name="" id="address" class="form-control input-sm">
<option value=""></option>
</select>
</div>
</form>
</div>
</div>
</div>
</section>
</body>
项目结构如下，
JavaScript 写在main.js 文件中，
$(document).ready(function () {
var selectedCurrency, walletName;
// if the currency is selected, make the address generate button active
$('#selectCurrency').change(function () {
selectedCurrency = $('#selectCurrency option:selected').text();
$('#generateAddress').removeAttr('disabled');
});
// if the address generate btn is active and clicked, open the modal
// to provide the wallet name
$('#generateAddress').click(function () {
$('#walletNameModal').modal();
});
// after the modal submission, get the wallet name
$('#addressNameSubmitBtn').on('click', function () {
walletName = $('#addressName').val();
// prints the value
console.log(walletName);
})
// doesn't print the value
console.log("Wallet = " + walletName);
});
console.log(walletName); 实际上会打印钱包名称，但是，当我外出时，console.log("Wallet = "+ walletName); 打印 Wallet = undefined。
我认为 walletName; 是全局的，因此，它还应该在控制台中打印值，然后是 undefined。这里有什么问题？
更新:
将变量移出范围后，我仍然有同样的问题，
var walletName;
$(document).ready(function () {
var selectedCurrency;
// some code
});
最佳答案
将您的代码更改为
var walletName;
$(document).ready(function () {
var selectedCurrency;
关于javascript - 在 JavaScript 的全局上下文中使用输入值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45706395/