html文件：
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
select {
200px;
background-color: teal;
height: 200px;
font-size: 20px;
}
.btn-box {
30px;
display: inline-block;
vertical-align: top;
}
</style>
</head>
<body>
<h1>城市选择：</h1>
<select id="src-city" name="src-city" multiple>
<option value="1">北京</option>
<option value="2">上海</option>
<option value="3">深圳</option>
<option value="4">广州</option>
<option value="5">西红柿</option>
</select>
<div class="btn-box">
<!--实体字符-->
<button id="btn1"> >> </button>
<button id="btn2"> << </button>
<button id="btn3"> ></button>
<button id="btn4"> < </button>
</div>
<select id="tar-city" name="tar-city" multiple>
</select>
<script src="jquery-1.12.4.js"></script>
<script>
$(function () {
$("#btn1").click(function () {
$("#src-city>option").appendTo("#tar-city");
});
$("#btn2").click(function () {
$("#src-city").append($("#tar-city>option"));
});
$("#btn3").click(function () {
$("#src-city>option:selected").appendTo("#tar-city");
});
$("#btn4").click(function () {
$("#src-city").append($("#tar-city>option:selected"));
});
});
</script>
</body>
</html>
