To loop through all the string inputs entered on a new line for a textarea control is not particularly challenging and uses basic array functionality to achieve this.

To see the code in action:

//trim off excess whitespace off the whole
$text = trim($_POST['textareaname']);

//explode all separate lines into an array
$textAr = explode("\n", $text);

//trim all lines contained in the array.
$textAr = array_filter($textAr, 'trim');

//loop through the lines
foreach($textAr as $line){
echo "$line";