blocks|key|5009997|text|如果你想在“代码级别”上看到区别，在A和B之间的关联中，A的实现(或者B，或者两者都有，取决于基数，可导航性，...)在OO中，lang将包含一个类型为B的属性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5009998|相反，在依赖项中，A可能有一个方法，其中一个参数是类型B。因此A和B没有链接，但更改B会影响依赖类A，因为A方法操作对象B的方式可能不再有效(例如，B更改了方法的签名，这会在类A中引发编译错误)。|5009999|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

If you want to see the difference at the "code level", in an association between A and B, the implementation of A (or B or both depending on cardinalities, navigability,...) in an OO lang would include an attribute of type B.

Instead in a dependency, A would probably have a method where one of the parameters is of type B. So A and B are not linked but changing B would affect the dependant class A since maybe the way the A method manipulates the object B is no longer valid (e.g. B has changed the signature of a method and this induces a compile error in the class A)

blocks|key|2894715|text|看看我问的这个问题可能会有帮助：does+an+association+imply+a+dependency+in+UML|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2894716|我的理解是：|2894717|关联|style|BOLD|2894718|public+class+SchoolClass{
++++/**+This+field,+of+type+Bar,+represents+an+association,+a+conceptual+link
+++++*++between+SchoolClass+and+Student.+(Yes,+this+should+probably+be
+++++*++a+List<Student>,+but+the+array+notation+is+clearer+for+the+explanation)
+++++*/
++++private+Student[]+students;
}|code-block|syntax|javascript|2894719|依赖项|2894720|public+class+SchoolClass{

++++private+Timetable+classTimetable;

++++public+void+generateTimetable(){
++++++++/*+
+++++++++*+Here,+SchoolClass+depends+on+TimetableGenerator+to+function,+
+++++++++*+but+this+doesn't+represent+a+conceptual+relationship.+It's+more+of
+++++++++*+a+logical+implementation+detail.
+++++++++*/
++++++++TimetableGenerator+timetableGen+=+new+TimetableGenerator();

++++++++/*
+++++++++*+Timetable,+however,+is+an+association,+as+it+is+a+conceptual+
+++++++++*+relationship+that+describes+some+aspect+of+the+data+that+the+
+++++++++*+class+holds+(Remember+OOP101?+Objects+consist+of+data+and+operations
+++++++++*+upon+that+data,+associations+are+UMLs+way+or+representing+that+data)
+++++++++*/
++++++++classTimetable+=+timetableGen.generateTimetable();
++++}

}|2894721|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/1152335/does-an-association-imply-a-dependency-in-uml^0|G|19|0|0|0|0|2|0|0|0|3|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|D|3|E|5|6|7|14|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|15|8|@$A|16|B|17|H|I]]|9|@]|C|$]]|$1|J|3|K|5|L|7|18|8|@]|9|@]|C|$M|N]]|$1|O|3|P|5|6|7|19|8|@$A|1A|B|1B|H|I]]|9|@]|C|$]]|$1|Q|3|R|5|L|7|1C|8|@]|9|@]|C|$M|N]]|$1|S|3|-4|5|6|7|1D|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]]]

It may be useful to see this question I asked: <a href="https://stackoverflow.com/questions/1152335/does-an-association-imply-a-dependency-in-uml">does an association imply a dependency in UML</a>

My understanding is:

Association

<pre><code>public class SchoolClass{
 /** This field, of type Bar, represents an association, a conceptual link
 * between SchoolClass and Student. (Yes, this should probably be
 * a List&lt;Student&gt;, but the array notation is clearer for the explanation)
 */
 private Student[] students;
}
</code></pre>

Dependency

<pre><code>public class SchoolClass{

 private Timetable classTimetable;

 public void generateTimetable(){
 /* 
 * Here, SchoolClass depends on TimetableGenerator to function, 
 * but this doesn't represent a conceptual relationship. It's more of
 * a logical implementation detail.
 */
 TimetableGenerator timetableGen = new TimetableGenerator();

 /*
 * Timetable, however, is an association, as it is a conceptual 
 * relationship that describes some aspect of the data that the 
 * class holds (Remember OOP101? Objects consist of data and operations
 * upon that data, associations are UMLs way or representing that data)
 */
 classTimetable = timetableGen.generateTimetable();
 }

}
</code></pre>

blocks|key|156232|text|简短的答案是:任何特定的源语言构造应该如何在UML中表示，并没有严格的定义。这将是相关语言的标准化UML概要文件的一部分，但遗憾的是，这些概要文件很少。下面是长长的答案。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|156233|在您的示例中，我恐怕不得不说“两者都不是”，这只是为了困难。A有一个B类型的成员变量，因此关系实际上是一个聚合或组合...或定向关联。在UML中，与命名的目标角色的定向关联在语义上等同于具有相应名称的属性。|offset|length|style|CODE|156234|​|156235|📷|atomic|156236|156237|根据经验，如果b在A的构造函数中被初始化，那么它就是一个聚合；如果它也在B的析构函数(共享生命周期)中被销毁，那么它就是一个组合。如果两者都不适用，那么它就是一个属性/定向关联。|156238|如果b不是A中的成员变量，并且没有对局部变量b进行操作(没有对其调用任何方法)，那么我会将其表示为一个依赖项：A需要B，但它没有该类型的属性。|156239|但是f()实际上调用的是在B中定义的方法。对我来说，这使得正确的关系成为一种依赖(+<<use>>+)，这是一种更特殊的依赖形式。|156240|最后，(无定向的)关联是两个类之间最弱的链接形式，正因为如此，我在描述源代码构造时不倾向于使用它们。当我这样做时，我通常在没有直接的源代码关系时使用它们，但这两个类仍然以某种方式相关。例如，这两个类负责同一较大算法的不同部分，但第三个类同时使用这两个部分。|156241|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/59d312f28006d62390e33dcbb69a625a.png|imageAlt^0|0|U|1|Y|1|0|0|0|1|0|0|0|7|1|9|1|10|1|0|2|1|5|1|M|1|1J|1|1M|1|0|2|3|D|1|16|7|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|15|8|@$D|16|E|17|F|G]|$D|18|E|19|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|1A|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|1B|8|@]|9|@$D|1C|E|1D|1|1E]]|A|$]]|$1|M|3|I|5|6|7|1F|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|1G|8|@$D|1H|E|1I|F|G]|$D|1J|E|1K|F|G]|$D|1L|E|1M|F|G]]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1N|8|@$D|1O|E|1P|F|G]|$D|1Q|E|1R|F|G]|$D|1S|E|1T|F|G]|$D|1U|E|1V|F|G]|$D|1W|E|1X|F|G]]|9|@]|A|$]]|$1|R|3|S|5|6|7|1Y|8|@$D|1Z|E|20|F|G]|$D|21|E|22|F|G]|$D|23|E|24|F|G]]|9|@]|A|$]]|$1|T|3|U|5|6|7|25|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|26|8|@]|9|@]|A|$]]]|W|$X|$5|Y|Z|10|A|$11|12|13|-4]]]]

The short answer is: how any specific source language construct should be represented in UML is not strictly defined. This would be part of a standardized UML profile for the language in question, but these are sadly few and far between. Long answer follows.

In your example, I'm afraid I would have to say "neither", just to be difficult. <code>A</code> has a member variable of type <code>B</code>, so the relationship is actually an aggregation or a composition... Or a directed association. In UML, a directed association with a named target role is semantically equivalent to an attribute with the corresponding name.

<img src="https://i.stack.imgur.com/hc17R.png" alt="enter image description here">

As a rule of thumb, it's an aggregation if <code>b</code> gets initialized in <code>A</code>'s constructor; it's a composition if it also gets destroyed in <code>B</code>'s destructor (shared lifecycle). If neither applies, it's an attribute / directed association.

If <code>b</code> was not a member variable in <code>A</code>, and the local variable <code>b</code> was not operatoed on (no methods were called on it), then I would represent that as a dependency: <code>A</code> needs <code>B</code>, but it doesn't have an attribute of that type.

But <code>f()</code> actually calls a method defined in <code>B</code>. This to me makes the correct relationship a <code>&lt;&lt;use&gt;&gt;</code>, which is a more specialized form of dependency.

Finally, an (undirected) association is the weakest form of link between two classes, and for that very reason I tend not to use them when describing source constructs. When I do, I usually use them when there are no direct source code relationships, but the two classes are still somehow related. An example of this might be a situation where the two are responsible for different parts of the same larger algorithm, but a third class uses them both.

blocks|key|2070069|text|依赖关系的定义非常松散。所以不会有代码表示。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2070070|：依赖关系是一种语义关系，其中对传入或独立建模元素的更改可能会影响依赖建模元素的语义。[1]|offset|length|style|BOLD|2070071|依赖是一种关系，表示单个或一组模型元素需要用于其规范或实现的其他模型元素。这意味着依赖元素的完整语义在语义上或结构上依赖于supplier元素的定义。|2070072|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Dependency_%2528UML%2529^0|0|0|1|17|3|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@$D|T|E|U|F|G]]|9|@$D|V|E|W|1|X]]|A|$]]|$1|H|3|I|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]]]

A dependency really is very loosely defined. So there would be no code representation.

Wiki: A dependency is a semantic relationship where a change to the influent or independent modeling element may affect the semantics of the dependent modeling element.<a href="http://en.wikipedia.org/wiki/Dependency_%28UML%29" rel="nofollow">[1]</a>

From the OMG Spec: A dependency is a relationship that signifies that a single or a set of model elements requires other model elements for their specification or implementation. This means that the complete semantics of the depending elements is either semantically or structurally dependent on the definition of the supplier element(s).

blocks|key|2070083|text|从Wiki获取它:依赖关系是一种较弱的关系形式，它表明一个类依赖于另一个类，因为它在某个时间点使用它。如果后者是前者的方法的参数变量或局部变量，则一个类依赖于另一个类。这与关联不同，在关联中，前者的属性是后者的实例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2070084|所以我认为这里的情况是关联，如果B是A的方法的参数变量或局部变量，那么它们是依赖的。|2070085|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Get it from Wiki: Dependency is a weaker form of relationship which indicates that one class depends on another because it uses it at some point of time. One class depends on another if the latter is a parameter variable or local variable of a method of the former. This is different from an association, where an attribute of the former is an instance of the latter.

So I think the case here is association, if B is a parameter variable or local variable of a method of the A, then they are dependency.

What is the difference between association and dependency? Can you give code examples?
What is the relationship between class A and B?

<pre><code>class A
{
 B *b;

 void f ()
 {
 b = new B ();
 b-&gt;f();
 delete b;
 }
}
</code></pre>

UML association and dependency

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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关联和依赖之间的区别是什么？你能给出代码示例吗？A类和B类之间是什么关系？class A{    B *b;    void f ()    {        b = new B ();        b->f();        delete b;    }}

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