jquery--获取input radio单选框的值

html

 <div class="layui-form-item">
      <label class="layui-form-label required">优惠券有效期</label>
      <div class="layui-input-block">
          <input type="radio" name="expire_type" lay-filter="expire_type" value="1" title="领取后N天有效" {if $row.expire_type=='1'}checked=""{/if}>
          <input type="radio" name="expire_type" lay-filter="expire_type" value="2" title="时间段" {if $row.expire_type=='2'}checked=""{/if}>
      </div>
 </div>

<div class="layui-form-item" id="expire_day">
      <label class="layui-form-label">有效天数</label>
      <div class="layui-input-block">
        <input type="number" name="expire_day" class="layui-input" placeholder="请输入有效天数" value="{$row.expire_day|default=''}">
      </div>
</div>
        
<div class="layui-form-item" id="expiry_date">
     <label class="layui-form-label">优惠券有效期</label>
     <div class="layui-input-block">
          <input type="text" name="expiry_date" data-date="" data-date-type="datetime" data-date-range="-" class="layui-input"  placeholder="请选择优惠券有效期" value="{$row.expiry_date|default=''}">
    </div>
  </div>

jquery

if($("[name='expire_type']:checked").val() == '1'){
        $('#expire_day').show();
        $('#expiry_date').hide();
}
   
if($("[name='expire_type']:checked").val() == '2'){ 
       $('#expire_day').hide();
       $('#expiry_date').show();
}