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java Programming Glossary: subtypeIs polymorphism possible without inheritance http://stackoverflow.com/questions/11732422/is-polymorphism-possible-without-inheritance to inheritance is classified as inclusion polymorphism or subtype polymorphism. Wikipedia provides a good definition In object.. provides a good definition In object oriented programming subtype polymorphism or inclusion polymorphism is a concept in type..
Use of '? extends ' and '? super ' in Collection generics [duplicate] http://stackoverflow.com/questions/12604477/use-of-extends-and-super-in-collection-generics is because all I know is that the list is some kind of subtype of Number but I don't know what that actual subtype is so how.. of subtype of Number but I don't know what that actual subtype is so how could I know what to add . For example take the following..
http://stackoverflow.com/questions/1817524/generic-arrays-in-java of supertype references is a supertype of an array of subtype references. That is Object is a supertype of String and a string..
Java interface extends Comparable http://stackoverflow.com/questions/2231804/java-interface-extends-comparable implements it to also implement Comparable with T and its subtypes . It would seem natural to write interface A T extends Comparable.. instance of Comparable that can be compared to one unknown subtype of T not that it can be compared to any subtype of T. But you.. unknown subtype of T not that it can be compared to any subtype of T. But you don't need that because a Comparable T can compare..
http://stackoverflow.com/questions/2723397/java-generics-what-is-pecs is that a Collection extends Thing could hold any subtype of Thing and thus each element will behave as a Thing when you.. Thing because you cannot know at runtime which specific subtype of Thing the collection holds. Case 2 You want to add things..
What is the difference between <E extends Number> and <Number>? http://stackoverflow.com/questions/2770264/what-is-the-difference-between-e-extends-number-and-number not covariant like arrays. That is in Java Double is a subtype of Number but a List Double is NOT a subtype of List Number.. Double is a subtype of Number but a List Double is NOT a subtype of List Number . A List Double however is a List extends Number..
What is a raw type and why shouldn't we use it? http://stackoverflow.com/questions/2770321/what-is-a-raw-type-and-why-shouldnt-we-use-it are subtyping rules for generics and List String is a subtype of the raw type List but not of the parameterized type List..
Compilers behave differently with a null parameter of a generic method http://stackoverflow.com/questions/3000177/compilers-behave-differently-with-a-null-parameter-of-a-generic-method then inferred to have type Object However Object is not a subtype of Comparable super Object and thus not within the bounds of..
Multiple wildcards on a generic methods makes Java compiler (and me!) very confused http://stackoverflow.com/questions/3546745/multiple-wildcards-on-a-generic-methods-makes-java-compiler-and-me-very-confu References Angelika Langer's Java Generics FAQ Which super subtype relationships exist among instantiations of generic types Can..
Java method dispatch with null argument http://stackoverflow.com/questions/377203/java-method-dispatch-with-null-argument complex. The constant null is of type nulltype which is a subtype of all types. So this nulltype extends String which extends..
Why does autoboxing make some calls ambiguous in Java? http://stackoverflow.com/questions/501412/why-does-autoboxing-make-some-calls-ambiguous-in-java Because after it has found the two matching methods only subtype conversion is used to determine the most specific method of..
Reference is ambiguous with generics http://stackoverflow.com/questions/5361513/reference-is-ambiguous-with-generics inference rules in 15.12.2.7 Now we substitute R and check subtype relations Parameter V Parameter V Field V V The 2nd line does..
http://stackoverflow.com/questions/55375/add-values-to-enum should be legal to supply a MyExtEnum value because it's a subtype but now what are you going to do when it turns out the value..
Is there a way to refer to the current type with a type variable? http://stackoverflow.com/questions/7354740/is-there-a-way-to-refer-to-the-current-type-with-a-type-variable current type. Is there a way to make T refer to the exact subtype so T should refer to B in class B class A T extends A foo class..
When do Java generics require <? extends T> instead of <T> and is there any downside of switching? http://stackoverflow.com/questions/897935/when-do-java-generics-require-extends-t-instead-of-t-and-is-there-any-down when the actual parameter can be SomeClass or any subtype of it. In your example Map String Class extends Serializable..
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