Get the text from textarea line by line?

http://stackoverflow.com/q/38102776/5076162

HTML

<textarea id="test" cols='21'></textarea>
<button id="button_test">Ok</button>

CSS

pre {
  color: green;
  background: #CCC;
}

JavaScript

$("#test").val("123e2oierhqwpoiefdhqwopidf");
var newString = $("#test").val().toString();
var splitString = parseInt($("#test").attr("cols"), 10) + 1;
var stringArray = [];
stringArray.push(newString);
var lineOne = stringArray[0].slice(0, splitString);
var lineTwo = stringArray[0].slice(splitString);
var lineBreakString = lineOne + "\n" + lineTwo;
console.log(lineTwo);
$('#test').after("<pre>" + lineBreakString + "</pre>");
//console.log(newString);