Question

我正在尝试在Matlab中创建一些对象。我习惯用Java编程，但能够在Matlab中完成这项工作对我的研究很有帮助。

所以，我有一个特定的课程：

classdef Lifter < handle


properties

    weightClass = 0;
    mean = 0;
    var = 0;
    nation = '';

end

methods

    function Lifter = Lifter(weightClass,mean,var,nation) %Constructor

        Lifter.weightClass = weightClass;
        Lifter.mean = mean;
        Lifter.var = var;
        Lifter.nation = nation;

    end

    function set.weightClass(this,weightClass)
    end       
    function set.mean(this,mean)
    end       
    function set.var(this,var)
    end       
    function set.nation(this,nation)
    end

    function value = get.weightClass(this)
        value = this.weightClass;
    end
    function value = get.mean(this)
        value = this.mean;
    end       
    function var = get.var(this)
        var = this.mean;
    end   
    function nation = get.nation(this)
        nation = this.nation;
    end

end

端

相当标准，并没有真正做很多事情。

所以，在另一页中，我有：

function Competition()

Lifter1 = Lifter(56,1,1,'USA')

end

然而，运行它会给出：

Lifter1 = 

Lifter with properties:

weightClass: 0
       mean: 0
        var: 0
     nation: ''

有任何帮助来弄清楚为什么没有从构造函数中正确初始化这些值会非常有帮助。

此外，如何在我的Lifter1对象上实际调用setter或getter方法的示例将会很有帮助。谢谢！

Answer 1

这些setter用于依赖属性（声明为create or replace trigger MAXSOME before insert on SOMENUMBERS for each row declare cursor pointer is select max(NUM) from SOMENUMBERS; x number; begin x := :new.NUM; if x > pointer.num then dbms_output.put_line('The new number ' || x || ' is greater than the greatest number in the table.'); elsif x := pointer then dbms_output.put_line('The new number ' || x || ' is the same as the greatest number in the table.'); else dbms_output.put_line(pointer.num || ' is still the largest number in the table.'); end if; end; /）。但是，您的安装人员没有实施（空），这意味着您的所有财产分配都不会做任何事情。这意味着属性保留在properties(Dependent)部分中声明的默认值。

稍后编辑

如果我必须实施该课程，请按以下代码执行：

properties

其余属性的代码类似。测试：

    classdef Lifter < handle


            % --- PUBLIC SECTION ---

            properties(Dependent)

                    weight_class;
            end;


            methods

                    function obj = Lifter(weight_class)
                            obj.weight_class = weight_class;
                    end;

                    function set.weight_class(obj, weight_class)
                            if ~isa(obj, 'Lifter') ...
                            || ~isscalar(obj) ...
                            || ~isvalid(obj)
                                    error('Lifter:Arg', '"obj" must be a scalar valid handle object of class "Lifter".');
                            elseif ~isnumeric(weight_class) ...
                            || ~isscalar(weight_class) ...
                            || ~isreal(weight_class) ...
                            || (weight_class <= 0) % + other value tests
                                    error('Lifter:Arg', '"weight_class" must be a numeric positive scalar.');
                            else
                                    obj.weight_class_ = double(weight_class);
                            end;
                    end;

                    function val = get.weight_class(obj)
                            val = obj.weight_class_;
                    end;
            end;


            % --- PRIVATE SECTION ---

            properties(Access=private)

                    weight_class_;

            end;

    end

Answer 2

你的主持人和吸气者不应该包含点（虽然我同意如果它有效会更优雅你的方式）：

function set.weightClass(this,weightClass)
end

可能（应该）：

function set_weightClass(this,weightClass)
end

如果我更换所有这些，它就能正常工作。

构造函数未在Matlab中分配值

2 个答案: