<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<select name="prl" id="prl" onchange="func6(this)">
<option value="1">a</option>
<option value="2">b</option>
<option value="3">c</option>
<option value="4">d</option>
<option value="5">e</option>
</select>
<div>
<textarea name="pro" id="pro" cols="30" rows="10"></textarea>
</div>
</body>
<script src="/static/jquery-3.3.1.js"></script>
<script>
function func6(ths) {
var data=ths.options[ths.selectedIndex].text
$(‘#pro‘).val(data)
}
</script>
</html>
原文：https://www.cnblogs.com/liweiblog/p/9019574.html