问题
This is very likely a bug, but I'm reporting it here for reference and for the slight chance of someone being able to propose a workaround.
IE 11 supports the placeholder attribute natively on textarea elements. That's great. But adding a new textarea with a placeholder to the DOM, it automatically puts the placeholder text into the textarea's field, too!
Here's the repro: http://jsfiddle.net/wE577/1/
回答1:
Fiddling around on jsfiddle, it turns out that from jQuery 1.9 onwards, this problem does not occur: http://jsfiddle.net/wE577/2/.
A weird problem indeed. Unfortunately, my google foo didn't turn up any bug reports on this.
Since at the moment, we cannot upgrade jQuery beyond 1.8.3 (although I hope we soon will), a workaround I came up with is setting the placeholder attribute after adding the new textarea element to the DOM, which works flawlessly.
回答2:
We are using jquery version 1.10.1 but still facing the issue,
<textarea placeholder='Max 250 characters'>Max 250 characters</textarea>
For this we emptied the value of textarea while clicking (or calling), like this
$('#textareaID textarea').val('');
来源：https://stackoverflow.com/questions/23375208/ie11-jquery-1-8-3-dynamically-added-textarea-with-placeholder-has-text-set-to