Capturez la valeur de TextArea
<textarea id="myTextarea">
Hello World
</textarea>
<script>
var x = document.getElementById("myTextarea").value;
</script>
Saf1
<textarea id="myTextarea">
Hello World
</textarea>
<script>
var x = document.getElementById("myTextarea").value;
</script>JS
document.querySelector("#textareaID").value;
JQuery
$("#textareaID").val();