How can I preserve a carriage return character in a text area?
textarea.value = "X" + String.fromCharCode("13") + "X";
textarea.value.charCodeAt(1); //returns 10, not 13
See here: http://jsfiddle.net/vah9e/
Arglanir
According to W3C Textarea api value, it seems that when invoking the .value attribute of textarea, any carriage return or line feed is transformed into a LINE FEED (10) character (in fact W3C says CRFL but it seems the browsers prefer only LF) - so a script can be platform-independent on line feeds.
In a form data, it seems that the fine feeds are transformed into CRLF (13+10).
W3C speaks also about a raw value but it's probably internal to any javascript engine and it seems it's not available in Javascript.
来源：https://stackoverflow.com/questions/28790525/carriage-return-in-textarea-retrieved-as-line-feed