Key words: getElementsByTagName querySelectorAll textarea <script>
ar1 = document.getElementsByTagName('textarea');
for (var i=0 ; i< ar1.length; i++) console.log(ar1[i].id);
ar2 = document.querySelectorAll("textarea");
for (var i=0 ; i< ar2.length ; i++) console.log(ar2[i].id);
</script>