jQuery验证依赖调用函数

Question

如果e_usagelow字段未填写，下面的jQuery验证代码应该检查用户必须输入e_usage字段的表单。我根据jQuery Validation - Two fields, only required to fill in one的示例编写了e-usage的依赖调用函数，但不知何故我的功能不起作用（例如，当 e_usagelow 为空时将鼠标放在 e-usage 字段上时，不会出现验证错误警告并且控制台显示值'true'）

出了什么问题？

请你帮忙。

html代码：

E-usage: <input id="e_usage" type="text" name="e_usage">
E-usage low: <input id="e_usagelow" type="text" name="e_usagelow" >

javascript代码：

$(document).ready(function () {
  $("#myForm").validate({
    rules: {
      'e_usage': {
        required: function (element) {
          console.log("validation: required: " + $("#e_usagelow").is(':empty'));
          return $("#e_usagelow").is(':empty');
        },
        minlength: 3,
        maxlength: 8,
        number: true
      },
      'e_usagelow': {
        required: true,
        minlength: 3,
        maxlength: 8,
        number: true
      }
    } //rules
  }); //validate()
}); //function

Answer 1

DEMO

将'e_usage' 更改为e_usage

和'e_usagelow' 到e_usagelow

id 没有用引号括起来

$(document).ready(function () {

    $("#myForm").validate({

        rules: {
            e_usage: { //removed quotes from id
                required: function (element) {
                    console.log("validation: required: " + $("#e_usagelow").is(':empty'));
                    return $("#e_usagelow").is(':empty');
                },
                minlength: 3,
                maxlength: 8,
                number: true
            },

            e_usagelow: { //removed quotes from id
                required: true,
                minlength: 3,
                maxlength: 8,
                number: true
            }

        } //rules


    }); //validate()

});