UML中类图的代码实现

Question

更新3

符号（单行，带有星号和箭头的钻石）在图表中的含义（来自Eric的ddd book p195）：

任何可以说明的代码示例都将受到赞赏。

Answer 1

钻石是组合物（也称为聚合物）或has-a关系。箭头是继承，或is-a关系。这条线是一个协会。这导致了一个问题：组合和协会之间的区别是什么。答案是组合更强，通常拥有另一个对象。如果主对象被销毁，它也会破坏它的组合对象，但不会破坏它的关联对象。

在您的示例中，工厂包含（has-a）LoanInvestment和LoanInvestment继承自（is-a）投资

以下是对class diagrams using UML的精彩描述。

这是c ++中的一个代码示例，我不太了解c＃，而且我可能会搞砸它。）

class Facility
{
public:
    Facility() : loan_(NULL) {}

    // Association, weaker than Composition, wont be destroyed with this class
    void setLoan(Loan *loan) { loan_ = loan; } 

private:
    // Composition, owned by this class and will be destroyed with this class
    // Defined like this, its a 1 to 1 relationship
    LoanInvestment loanInvestment_;
    // OR
    // One of the following 2 definitions for a multiplicity relation
    // The list is simpler, whereas the map would allow faster searches
    //std::list<LoanInvestment> loanInvList_;
    //std::map<LoanInvestment> loanInvMap_;

    Loan *loan_:
    // define attributes here: limit
};

class Loan
{
public:
    // define attributes here: amount
    // define methods here: increase(), decrease()
private:
    // 1 to 1 relationship, could consider multiplicity with a list or map
    LoanInvestment loanInvestment_;
};

class Investment
{
    // define attributes here: investor, percentage
};

class LoanInvestment : public LoanInvestment
{
    // define attributes here
};