Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs subclassing Interfaces: subtyping without inheritance [see also section]
L Subtyping
The definition of subtyping depends on the definition of strong versus weak specifications In Java subclassing, Java subtyping, and true subtyping later )
lec
Why we like subclasses? True subtypes vs Java subtypes Inheritance vs Composition Substitution Principle Interfaces and Abstract Classes
lect subtyping
Subtyping and Inheritance in Java Prakash Panangaden November myInt is the superclass and that gaussInt is the subclass class gaussInt extends myInt {
subtyping and inheritance in java
In Java we have that subclassing induces subtyping (see below) Comparing OO-style vs datatypes in functional programming Let us assume we want to write
java
Differences between subtypes and subclasses for all m: U → V in T, there is an m: U' → V' in S such that V' New wild card types in Java 1 5 also definable in
NEPLS
inheritance does not define any subtyping relation, whereas in languages such as JAVA and C++, inheri- Both C++ and JAVA have mechanisms that allow some classes and functions to have greater access priv- ileges to environment (V)
pdf?md =cc ea d d fb a ab b f b&pid= s . S X main
Thus far we have assumed that only object types have subtypes, and that subtypes are q:V' } masquerading as an element of type { m:S; n:T; p:U } as a record of type Suppose C is a class with a subclass CSub, and suppose the method method- OfCSubOnly() Java's unsafe subtyping rule for arrays allows any array
chap
Inheritance versus Subtyping ▫ Subtyping Terminology: Subclassing = Subtyping + Inheritance Dynamic binding: Eiffel, Java, Scala, dynamically- typed
lecture inheritance
This is also called subclassing • In Java: class B extends A B is a subtype of A B inherits from A class C Inheritance vs composition: Example 1 Lecture #3:
OOP lecture
Subtyping vs. subclassing. Substitution (subtype) — a specification notion – Every subclass is a Java subtype. • But not necessarily a true subtype. Page ...
https://www.cs.rpi.edu/academics/courses/spring21/csci2600/handout-files/files_29_03/SubtypePolymorphism.pdf
Subclasses can lead to subtype relationships. Page 4. 4 reminder: why we like true subtypes versus Java subtypes. Java requires type equality for parameters.
(For the time being we will talk about subtyping; we'll return to the differences between. Java subclassing Java subtyping
Subtyping vs. subclassing. Substitution (subtype) — a specification notion. – B is – Every subclass is a Java subtype. • But not necessarily a true subtype.
Subtyping vs. subclassing. Substitution (subtype) — a specification notion • In a Java subtype/subclass each corresponding method has: – Same argument ...
Subtyping vs. subclassing. Substitution (subtype) — a specification notion – Every subclass is a Java subtype. • But not necessarily a true subtype. Page ...
– every subclass is a Java subtype. – but not necessarily a true subtype SUBTYPES VS SUBCLASSES. Page 23. Substitution principle for methods. Constraints on ...
SUBTYPES VS SUBCLASSES. Page 4. Substitution principle for classes. If B is a • In a Java subtype each corresponding method has: – same argument types. • if ...
• Inheritance (subclass). – Abstract out repeated code. – Enables incremental changes to classes. • Every subclass is a Java subtype. – But not necessarily a
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing ... Inheritance (subclass) — an implementation notion.
https://www.cs.rpi.edu/academics/courses/spring21/csci2600/handout-files/files_29_03/SubtypePolymorphism.pdf
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing ... Inheritance (subclass) — an implementation notion.
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing ... Inheritance (subclass) — an implementation notion.
This is not the same as a Java subtype. – Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing.
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing ... Inheritance (subclass) — an implementation notion.
In Java this usually means interfaces and sometimes means abstract base classes. • In Java
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing ... Inheritance (subclass) — an implementation notion.
Every subclass is a Java subtype Changes in superclass can break subclass (“fragile base class”). Subtyping is the ... public void put (K key V value);.
SUBTYPES VS SUBCLASSES In a Java subtype each corresponding method has: ... Java subtyping does not guarantee that overridden methods.
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs subclassing Java purposely merges these notions for classes:
Java types are classes interfaces or primitives Java has its own notion of subtype (which involves only classes and interfaces) This is a weaker notion than
A function or a data type to be written generically so that it can handle values uniformly without depending on their type • C++ Templates Java Generics •
A method expecting an object of type A will accept objects of type BC or D This gives increased generality to the code 1There are other kinds most notably
Classes and types Classes in Java play two distinct roles they introduce a “type” and they define code consisting of constructors fields and methods Consider
Why we like subclasses? True subtypes vs Java subtypes Inheritance vs Composition Substitution Principle Interfaces and Abstract Classes
S is a subtype of T (written S
11 nov 2003 · In this lecture we look at the relationship between inheritance and sub- typing in more detail First we look at the tradeoffs between
“Width” subtyping: A supertype can have a subset of fields with the same types 2 “Permutation” subtyping: A supertype can have the same set of fields with
Java subtypes that are not true subtypes are confusing and dangerous Subtyping vs. subclassing Java purposely merges these notions for classes:.
What is the difference between subclass and subtype Java?
Subtyping is a means of refining the protocol. Subclassing is a means of differential code re-use, i.e. re-using code by only describing the difference in behavior.What is the difference between subclasses and subtypes?
Subclasses allow one to reuse the code inside classes - both instance variable declarations and method definitions. Thus they are useful in supporting code reuse inside a class. Subtyping on the other hand is useful in supporting reuse externally, giving rise to a form of polymorphism.What is a subtype in Java?
Subtyping is a key feature of object-oriented languages such as Java. In Java, one type is a subtype of another if they are related by an extends or implements clause.- A supertype is a generic entity type that has a relationship with one or more subtypes. A subtype is a sub-grouping of the entities in an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other subgroups.
Lecture 12 Subtypes and Subclasses