AngularJS是无关范围变量的设置值

我有下面的angular代码来初始化angular表单。它返回一个几乎为空的记录,除了几个日期和员工信息。

我试图创建一个范围变量,以便在填写表单后保留原始记录以进行比较。这就是$scope.TechSheetInfoStatic的用途。

出于我们在这里的目的,我将$scope.TechSheetInfo.Customer.Email设置为一个虚拟值。在更新$scope.TechSheetInfo时, 还更新了$scope.TechSheetInfoStatic . 为什么?

     $scope.initializeTechSheet = function() {
        $scope.TechSheetInfo = [];
        $scope.TechSheetInfoStatic = [];
        $scope.customerIDDisabled = false;
        $scope.orderIDDisabled = false;

        const successFunction = function(response) {
            $scope.TechSheetInfo = response.data;
            $rootScope.customerInfo = response.data.Customer;
            $scope.TechSheetInfoStatic = response.data;
            $scope.TechSheetInfo.Customer.Email = "bobo@bobo.com";
            alert(JSON.stringify($scope.TechSheetInfo.Customer));
            alert(JSON.stringify($scope.TechSheetInfoStatic.Customer));

        };

        const failureFunction = function(response) {
            //console.log('Error' + response.status);
        };

        TechSheetFactory.ITS(successFunction, failureFunction);
    };