How can I capture the input in a <textarea></textarea> input field? With JavaScript?

Answer 1

<textarea id="someField">value goes here</textatea>

Var value = document.getElementById("someField").value;
Console.log(value)

Or if you have jQuery:
Var value = $("#someField").val();

Answer 2

U can get the access directly by id like:
var val = someField.value;