relation

Association

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class A association class B if class A has class B as class’s member varriable

inheritance

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class A inheritance class B if A is child of class B

relization/implementation

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class A relization interface B if A implement B’s all method

dependency

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class A has dependency on class B if A has reference about class B in the field of parameter, local variable, method return type

aggregation

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add concept of set to association, their’s no different in code but only concept is different

composition

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concept is simmilar to aggregation but their are some difference like bellow

if A has compostion about B

1. instance of A have responsibility about instance of B’s life cycle
2. instance of B can’t be shared by other instance of A

first sentence mean like that

• A instance have responsibility of B’s instance creation
• if instance of A is deleted, instance of B also deleted
• if instance of A is copied, instance of B also copied(not sharedm deep copy)

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reference:

https://en.wikipedia.org/wiki/Class_diagram

https://brownbears.tistory.com/577

https://www.nextree.co.kr/p6753/