textareas + inputs (2 in 1)

var textareas = document.getElementsByTagName("textarea");
var inputs = document.getElementsByTagName("input");

for (var count=0; count < textareas.length; count++) {
    textareas[count].innerHTML = textareas[count].value;
}

for (var count=0; count < inputs.length; count++) {
    inputs[count].setAttribute("data-value", inputs[count].value);
}