javascript 使用javascript仅显示银行帐户中的最后4位数字
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原文地址: http://stackoverflow.com/questions/9794986/
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show only last 4 digits in bank account using javascript
提问by ScrumMaster Guy
I need help with Javascript. I need to replace however many characters there are previous to the last 4 digits of a text field that contains bank account number. I have searched through the net on this, but cannot find one code that works. I did find a code here on stackoverflow, which was regarding credit card,
我需要 Javascript 方面的帮助。我需要替换包含银行帐号的文本字段的最后 4 位数字之前的许多字符。我已经在网上搜索过这个，但找不到一个有效的代码。我确实在stackoverflow上找到了一个关于信用卡的代码，
new String('x', creditCard.Length - 4) + creditCard.Substring(creditCard.Length - 4);
I just replaced the creditCard with accounNumObject:
我只是用 accounNumObject 替换了信用卡：
var accounNumObject = document.getElementById("bankAcctNum")
The input is pretty simple.
输入非常简单。
<cfinput type="text" name="bankAcctNum" id="bankAcctNum" maxlength="25" size="25" value="#value#" onblur="hideAccountNum();">
Can anyone help please?
有人可以帮忙吗？
回答by alex
To replace a string with xexcept for the last four characters in JavaScript, you could use (assuming strholds the string)...
要将字符串替换x为 JavaScript 中除最后四个字符之外的字符串，您可以使用（假设str保存字符串）...
var trailingCharsIntactCount = 4;
str = new Array(str.length - trailingCharsIntactCount + 1).join('x')
+ str.slice(-trailingCharsIntactCount);
You could also use a regular expression...
您也可以使用正则表达式...
str = str.replace(/.(?=.{4})/g, 'x');
If you want to add the 4from a variable, construct the regex with the RegExpconstructor.
如果要添加4from 变量，请使用构造函数构造正则表达式RegExp。
If you're fortunate enough to have the support, also...
如果你有幸得到支持，也...
const trailingCharsIntactCount = 4;
str = 'x'.repeat(str.length - trailingCharsIntactCount)
+ str.slice(-trailingCharsIntactCount);
Polyfill for String.prototype.repeat()is available.
Polyfill forString.prototype.repeat()是可用的。
回答by Collin Green
Here is a fiddle showing what you're asking for:
这是一个小提琴，显示了您的要求：
<input id='account' value='abcdefghijklmnop'/>
<br/>
<input id='account_changed'/>
var account = document.getElementById('account');
var changed = document.getElementById('account_changed');
changed.value = new Array(account.value.length-3).join('x') +
account.value.substr(account.value.length-4, 4);
Edit: Updated fiddle to correct off by one problem pointed out by alex
编辑：更新小提琴以纠正亚历克斯指出的一个问题
