I guess you want this type of output.
$(document).ready(function () {
$(".submit").click(function() {
var a = $(this).siblings(".mdl-textfield__input").val();
if(a != ''){
function stripHTML(text){
var regex = /(<([^>]+)>)/ig;
return text.replace(regex, "");
}
var no_tags = stripHTML(a);
$(".mdl-textfield__label").text("Your value is:"+no_tags);
var a = $(this).siblings(".mdl-textfield__input").val("");
}
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label"> <textarea class="mdl-textfield__input" type="text" rows="3" id="emailbody" data-required="true"></textarea><br><button class="btn submit btn-primary">Submit</button><br><label class="mdl-textfield__label" for="sample5"></label></div>