OOPs difference faqs- 2
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The document compares several concepts in programming: 1. Events can be used in interfaces but delegates cannot. Events have add/remove accessors while delegates do not. Events have a specific signature while delegates do not. 2. A class is a template for objects while an object is a real implementation in memory. Classes define logic for reuse while each object has its own data. 3. A private constructor is called after object creation while a static constructor initializes static members before any objects are created. Private constructors initialize each object while static constructors run only once. 4. Properties represent data via getters/setters while methods perform actions via defined signatures. 5. The singleton pattern ensures
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OOPs difference faqs- 2
- 1. Difference between Events and Delegates S.No Events Delegates 1 Event can be used in an Delegate cannot be used in an interface definition interface definition 2 Event can only be invoked from Delegates can be invoked from child the class that declares it classes and clients. 3 Event comes with its pair of There is no pair of accessors concept accessors i.e Add and Remove. in delegates. An event is always assigned and unassigned with a += and -= operator. 4 Event has a restrictive signature Delegates do not have restrictive and must always be of the form signature as like events Event (object source, EventArgs args) Difference between Class and Object S.No Class Object 1 It is a datatype that contains the It is a chunk of memory that programming logic. implements the class logic. 2 Class is visible in the source code Object is in the RAM and not and resides in hard disk. visible in source code. 3 Class is like a template or blueprint It is the real world implementation of the object. It implements of the class. Each object has its reusability,encapsulation, own copy of data. inheritance 4 Example:Button is a class with Example: Button1, Button2 are the properties like Text,BackColor, objects of Button class. events like click, methods like Focus 5 We can create subclasses We cannot create sub-objects Difference between Private and Static Constructor S.No Static constructor Private constructor 1 A static constructor is called Private constructor is called after the before the first instance is instance of the class is created. created. i.e. global initializer. 2 Static constructor will be called Static members will not be initialized first time when the class is either by private or public referenced.Static constructor is constructor. used to initialize static members of the class. 3 The static constructor will only be The private constructor will be executed once. executed each time it is called.
- 2. Difference between properties and methods S.No Properties Methods 1 Properties are used to represent Methods are used to performs actions data 2 Properties are created by using Methods create like public void getter and setter i.e., get{} and method1(parameter list here) set{} Difference between Singleton Pattern and a static class S.No Singleton Pattern static class Singleton pattern maintains single We cannot create instance for static instance. class. 2 A singleton can extend classes and A static class cannot . implement interfaces. Note: It can extend classes, but it does not inherit their instance members. 3 A singleton can be initialized lazily A static class is generally initialized or asynchronously. when it is first loaded, leading to potential class loader issues. 4 Singletons can be handled static class cannot be handled polymorphically without forcing polymorphically. their users to assume that there is only one instance. 5 Singleton Class can have value Static are always just shared and have when Class object instantiated no instance but multiple references. between server and client, such a way if three client want to have a shared data between them Singleton can be used.Thats why singleton class can be used for state mangement in stateless scenarios like shopping cart scenario. 6 We can pass singleton object as We cannot pass parameter in static parameter class 7 Singleton provides flexibility and Static classes once defined could not also provides sort of a mechanism accomodate any future design to control object creation based on changes as by design static classes various requirements. They can be are rigid and cannot be extended. extended as well if need arises. In other words we are not always tied to a particular implementation. With Singleton we have the flexibility to make changes as when situation demands.