<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
select {
width: 200px;
height: 300px;
font-size: 22px;
background-color: #80ff45;
}
</style>
<script src="jquery.min.js"></script>
</head>
<body>
<!-- multiple 允许多选 -->
<select name="" id="sel1" size="4" multiple="multiple">
<option value="">香蕉</option>
<option value="">大鸭梨</option>
<option value="">苹果</option>
<option value="">大西瓜</option>
</select>
<button>>>></button>
<button><<<</button>
<button>></button>
<button><</button>
<select name="" id="sel2" size="4" multiple=“multiple></select>
</body>
</html><script>
$("button").eq(0).click(function () {
$("#sel2").append($("#sel1 option"))
});
$("button").eq(1).click(function () {
$("#sel1").append($("#sel2 option"))
});
$("button").eq(2).click(function () {
$("#sel2").append($("#sel1 option:selected"))
});
$("button").eq(3).click(function () {
$("#sel1").append($("#sel2 option:selected"))
});
</script> 