我有一个银行余额文本字段,我想根据存款/取款不断更新。这是我的代码:
<label>Bank Balance:</label>
<br />
<input type="text" id="bankBalance" value="1000" />
<br />
<br />
<button id="deposit">Deposit</button>
<button id="withdraw">Withdraw </button>
var balance = document.getElementById('bankBalance').value;
balance = Number(balance);
var withdraw = document.getElementById('withdraw');
deposit.addEventListener('click', depositCash);
function depositCash () {
var depositAmt = prompt('How much would you like to deposit?');
depositAmt = Number(depositAmt);
balance = depositAmt + balance;
return balance;
}
未收到错误。为什么这不起作用?我将余额和depositAmt变量都转换为数字并添加它们。
谢谢!
答案 0 :(得分:1)
你不能这样做:
document.getElementById('bankBalance').value = balance
您需要将值设置回文档元素,例如
<itunes:length></itunes:length>