I have a small function I found that takes a string from a textarea and then puts it into a canvas element and wraps the text when the line gets to
Use the following:
var enteredText = document.getElementById("textArea").value;
var numberOfLineBreaks = (enteredText.match(/\n/g)||[]).length;
alert('Number of breaks: ' + numberOfLineBreaks);
DEMO
Now what I did was to split the string first using linebreaks, and then split it again like you did before. Note: you can also use jQuery combined with regex for this:
var splitted = $('#textArea').val().split("\n"); // will split on line breaks
Hope that helps you out!