JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="ptest">
GET / HTTP/1.1 
 Host: localhost:8888 
 Connection: keep-alive 
 Cache-Control: max-age=0 
 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/535.2 (KHTML,like Gecko) Chrome/15.0.874.121 Safari/535.2 
 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 
 Accept-Encoding: gzip,deflate,sdch 
 Accept-Language: en-US,en;q=0.8 
 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 
</textarea>

JavaScript

var lines = $("#ptest").val().split("\n");  
alert(lines.length);