如何防止 Jquery 追加不止一次
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How to prevent Jquery append more than once
提问by kirby
I have some jQuery that checks if the user inputted a correct email address. The user can then go back and change his/her email if it is not valid. However, my code will result in the same error messege twice because the error keeps getting appended inside my errorsdiv. How can I change this to only allow the error to be appended once? I also would like to remove the error if the emailvariable is true. There are also other validation errors being placed in this div.
我有一些 jQuery 来检查用户是否输入了正确的电子邮件地址。如果电子邮件无效，用户可以返回并更改他/她的电子邮件。但是，我的代码将导致两次相同的错误消息，因为错误一直附加在我的errorsdiv 中。如何更改此设置以仅允许附加一次错误？如果email变量是true. 此 div 中还存在其他验证错误。
jQuery:
jQuery：
var email = $('#email').val();
email = validateEmail(email);
if (email = "false") {
$('#errors').append("<p>Please enter a valid email</p>");
}
validateEmailwill return either trueor falsedepending on whether the email is valid.
validateEmail将返回true或false取决于电子邮件是否有效。
回答by redmoon7777
var email = $('#email').val();
email = validateEmail(email);
if (email == "false"){
$('#email_error').remove();
$('#errors').append("<p id='email_error'>Please enter a valid email</p>");
}
回答by Bhavesh Gangani
when u append the email error, specity it with a class "emailerror",
当您附加电子邮件错误时，请使用“ emailerror”类指定它，
$('#errors').append("<p class="emailerror">Please enter a valid email</p>");
but before append, just remove that error which have class "emailerror"
但在追加之前，只需删除具有“emailerror”类的错误
var email = $('#email').val();
email = validateEmail(email);
if (email = "false"){
$('#errors .emailerror').remove();
$('#errors').append("<p class="emailerror">Please enter a valid email</p>");
}
回答by Shree
Try clearing the value before appending new information, ie new errors:
在附加新信息之前尝试清除该值，即新错误：
$('#errors').val('');
回答by Purag
Use html()or text()to set the content of the errors div:
使用html()或text()设置错误的内容div：
$('#errors').html("<p>Please enter a valid email</p>");
And to not display anything when emailis true, add an elseto your ifstatement:
并且在emailis时不显示任何内容true，请else在您的if语句中添加一个：
if (email === "false"){
$("#errors").html("<p>Please enter a valid email</p>");
} else {
$("#errors").html("");
}
Also note that I used ===instead of =. This is because using a single equals sign (=) will just set the variable emailto falseand not actually check for equality.
另请注意，我使用了===而不是=. 这是因为使用单等号（=）将只设置变量email来false，而不是实际检查是否相等。
回答by Kushal Jayswal
More appropriate way is to remove all the appended code from DOM tree:
更合适的方法是从 DOM 树中删除所有附加的代码：
Try this:
试试这个：
var email = $('#email').val();
email = validateEmail(email);
if (email == "false"){
$('#email_error').parent().remove();
$('#errors').append("<p id='email_error'>Please enter a valid email</p>");
}
回答by Olagoke Mills
all you need to do is add a $('.appended').remove()right after your conditional, then in the text you are appending, use a ptag and add a class="appended"it works well
你需要做的就是$('.appended').remove()在你的条件之后添加一个right，然后在你附加的文本中，使用一个p标签并添加一个class="appended"它运行良好
