javascript - 如何检查属性的 null 和 undefined 两个值？

Question

我有两个属性，我需要为每个属性检查 null 和 undefined，我如何在 if else 语句中使用它？

主要.js

   var validateControlRating = function () {
            if ( ($scope.controlProcessRatingDTO.controlPerformanceRatingKey === null || 
                $scope.controlProcessRatingDTO.controlPerformanceRatingKey === undefined)
                &&
               ($scope.controlProcessRatingDTO.controlDesignRatingKey === null ||
                $scope.controlProcessRatingDTO.controlDesignRatingKey === undefined) ) {
              $scope.caculatedRatingDiv = false;
            } else {
            $http.get('app/control/rest/calculateControlEffectiveness/' + $scope.controlProcessRatingDTO.controlDesignRatingKey + '/' + $scope.controlProcessRatingDTO.controlPerformanceRatingKey).success(function (data) {
                $scope.calcaulatedRating = data;
            }, function (error) {
                $scope.statusClass ='status invalid userErrorInfo';
                var errorMessage = error.data.errorMsg;
                if (error.data.techErrorMsg) {
                    errorMessage = error.data.techErrorMsg;
                }
                $scope.statusInfo = errorMessage;
             });
            $scope.ratingValidationMsg = '';
            $scope.ratingWinValidationClass = 'valid';
            $scope.caculatedRatingDiv = true;
            $scope.enableRatingSave = false;
        }
    };

Answer 1

在javascript中有点乏味，你必须写每个条件，并使用括号等

if ( ($scope.controlProcessRatingDTO.controlPerformanceRatingKey === null || 
      $scope.controlProcessRatingDTO.controlPerformanceRatingKey === undefined)
      &&
     ($scope.controlProcessRatingDTO.controlDesignRatingKey === null ||
      $scope.controlProcessRatingDTO.controlDesignRatingKey === undefined) ) {...

---

或者只是

if ([null, undefined].indexOf( $scope.controlProcessRatingDTO.controlPerformanceRatingKey ) === -1
    &&
    [null, undefined].indexOf( $scope.controlProcessRatingDTO.controlDesignRatingKey ) === -1) {...