您可以使用each循環(huán)遍歷選項(xiàng)并檢查 select-box 的值car是否與 select-box 相同，country具體取決于 thisshow()或hide()options 。
演示代碼：
$(function() {
$('#Country_Select').on('change', function() {
var val = this.value;
$('#Cars_Select option').each(function() {
//checking value of opton in cars selct is same
if ($(this).val() == val) {
$(this).show(); //show it
} else {
$(this).hide(); //hide other
}
})
})
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
// Country select
<select id="Country_Select" class="form-control">
<option selected="true" disabled="false">Choose Country</option>
<option value="0001">France</option>
<option value="8ebd9ec1-b121-44e9-a530-42f227359913">Germany</option>
<option value="4dda2683-83c6-48c8-af9b-0a96991b7c8b">New Zealand</option>
</select>
// Cars
<select id="Cars_Select" class="form-control">
<option selected="true" disabled="false">Choose Cars</option>
<option value="0001">Renauld</option>
<option value="0001">Mini</option>
<option value="0001">Paris</option>
<option value="8ebd9ec1-b121-44e9-a530-42f227359913">BMW</option>
<option value="8ebd9ec1-b121-44e9-a530-42f227359913">Audi</option>
<option value="8ebd9ec1-b121-44e9-a530-42f227359913">Mercedes</option>
<option value="8ebd9ec1-b121-44e9-a530-42f227359913">Benz</option>
<option value="4dda2683-83c6-48c8-af9b-0a96991b7c8b">Kiwi Auto</option>
</select>
