javascript - 未捕获的类型错误 : Cannot read property 'basePrice' of undefined

Question

我不确定错误(Uncaught TypeError:无法读取未定义的属性“basePrice”)意味着什么，因为该值在第一部分中已明确定义。

当我展开错误消息时，它会标记更新的价格，然后是两个匿名函数。我不确定是否应该查找拼写错误，或者是否使用了不正确的逻辑。

 <script>
(function() {

  var plans = {
    basic: {
      pricingChart: false,
      pricingChart2: false,
      basePrice: 0
    },
    standard: {
      pricingChart: false,
      pricingChart2: false,
      basePrice: 2.99
    },
    premium: {
      pricingChart: true,
      pricingChart2: false,
      basePrice: 49.99
    },
    enterprise: {
      pricingChart: true,
      pricingChart2: true,
      basePrice: 500
    }
  };

  var viewerLevels = {
    500: 10.99,
    2500: 10.99,
    5000: 29.99,
    10000: 39.99
  };

  var userLevels = {
    1: 10.99,
    2: 20.99,
    3: 30.99,
    4: 40.99
  };


    var selectedPlan = "free";
    var viewerLevel = null;
    var userLevel = null;

      $( ".plan .select-button" ).on( "click", function( event ) {
        selectedPlan = $( this ).closest( ".plan" ).attr( "data-plan" );
        var planInfo = plans[ selectedPlan ];

        if ( planInfo.pricingChart ) {
          $( "#pricingChart" ).removeClass( "not" );
        } else {
          $( "#pricingChart" ).addClass( "not" );
          viewerLevel = null;
        }

        if ( planInfo.pricingChart2 ) {
          $( "#pricingChart2" ).removeClass( "not" );
        } else {
          $( "#pricingChart2" ).addClass( "not" );
        userLevel = null;
        }

        var showPricingChart = "#topPricingChart";
        if ( planInfo.pricingChart ) {
          showPricingChart = "#pricingChart";
        }

        $( "html,body" ).animate({
          scrollTop: $( showPricingChart ).offset().top
        }, "slow" );

        updatePrice();
      });

      $( ".pricingLevel" ).on( "click", function() {

        viewerLevel = $( this ).attr( "data-viewer" );

        updatePrice();  
      });

      $( ".pricingLevel2" ).on( "click", function() {
        userLevel = $( this ).attr( "data-user" );
        updatePrice();
      });

          function updatePrice() {
            var basePrice = plans[ selectedPlan ].basePrice;

            var viewerPrice = 0;
            if ( viewerLevel ) {
              viewerPrice = viewerLevels[ viewerLevel ];
            }

            var userPrice = 0;
            if ( userLevel ) {
              userPrice = userLevels[ userLevel ];
            }

            var totalPrice = basePrice + viewerPrice + userPrice;
          $( ".pricingLargeAmount" ).text( totalPrice );
          }

        updatePrice();
})();

</script>

Answer 1

该错误意味着 plans[ selectedPlan ] 未定义。

selectedPlan == "free" 且 plans.free 不存在。