class Foo {}
class Bar {
Foo foo;
}
Since Foo is a type of field of Bar, can we safely claim that Bar depends on Bar? What if foo == None? Does that mean Bar no longer depends on Bar?
1 Answer
This comes down to the difference between composition and aggregation. In the example you have
class Foo {}
class Bar {
Foo foo;
}
Here, Bar can exist independent of Foo because foo can be null - a weak dependence.
However, if you had the same relationship defined this way:
class Foo {}
class Bar {
Foo foo;
Bar(Foo foo){
this.foo = foo;
}
}
then, it is a composition relationship, where Bar can not exist without Foo.
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