polymorphism vs encapsulation

lowercase, Uppercase Error "Class a{Public Function test () {Echo ' A_test ';}}Class B extends a{Public Function __construct () {Both of these methods are OKA::test ();Parent::test ();}}$b =new B ();5, if the method of a subclass (derived class) is exactly the same as the method of the parent class (public,protected), we are called method overrides or method overrides (override) to see the polymorphism belowIii. PolymorphismCases:Copy CodeThe code is

class's member variables, can only be used in this class, through the set, get methods to provide access to the external portalBenefits: 1. Access to data only by means of the specified method2. Hide the specific implementation details of the class3. Easy to modify the implementation4. Easy to join control statements(v) Polymorphism:polymorphic constituent conditions: 1. To have class inheritance2. To have a method of rewriting3. A reference to the parent class object to the child classLook at

that certain methods must be provided in these classes.2, definition: interface keyword.3. Basic syntax: [modifier] Interface Interface Name [extends parent interface 1, parent Interface 2 ...]{???? 0 to more constant definitions ...???? 0 to the definition of multiple abstract methods ...}4. Constants/methods: The attributes in the interface are constants, even if the public static final modifier is not added to the definition, the system is automatically added.5, using interface: A class can

JS is a very flexible language, do not talk about polymorphism (or that it is polymorphic)PackagingConcept:Closed part, no direct access to the outside worldIndirect access to private parts through open sectionsExample:Not encapsulated: All properties of the constructor are openfunction Girl (NAME,BF) { this. Name = name; this. bf = BF;} var New Girl ("Lin Daiyu", "Jiabaoyu" + "Love" + GIRL.BF); // lin Daiyu love Jia BaoyuEncapsulation: Encaps

Data encapsulation, inheritance and polymorphism are the three main characteristics of object-oriented.Data encapsulation:In a class, such as the student class (initialization and name and score two properties), each instance has its own name,score of the data. We can access this data through functions, such as printing a student's score. Directly define an output function, output name and corresponding sco

the following class, or an inheritance relationship with the following class, or it will cause a compilation error.2, usually first use instance to determine whether an object can be coerced type conversion, and then forced type conversion, thus guaranteeing the correctness of the program.7. Initialize the code block: Initializes a class or an instance.Syntax: "modifier" {Initialize code block}; Note: Modifiers can only be static, or can be omitted.Features: No name, so cannot be referenced, as

($s); */Encapsulation of the second assignment output/* $s->age = 20;Var_dump ($s); */Value output/* $s->age = 20;Echo $s->age; */Object-oriented instancesEg: a large circle contains a small circle, a circle radius of 10, a small circle radius of 5, the area of the circle minus the small circle.Class circle{Public $r;Public $area;Public $cir;Public Function area () {return 3.14* $this->r* $this->r;}Public Function Cir () {return 2*3.14* $this->r;}Pub

and does not represent the class (2) Inheritance: Concept: Subclasses can inherit everything from the parent class Feature: Single inheritance A subclass can have only one parent class, and a parent class may have multiple subclasses (all parent classes are object) Base keyword Sealed keywords: Sealed class This class cannot be inherited Part of class: Partial can split a class into multiple parts, and put them in multiple files namespace namespaces are equivalent to virtual folders (3)

1. EncapsulationIn many object-oriented languages, object encapsulation is implemented with syntax parsing, which may provide keywords such as private,public,protected to control access rights.However, JavaScript does not provide these keywords and can only change the scope of variables by closures to implement encapsulation characteristicsPrivate variables. Use closures to implement a private variable var

new method of subclass cannot be called. Downward Transformation The premise for downward transformation is that the parent class has been transformed up; otherwise, compilation errors may occur, Parent Class Object = new subclass () Subobj = object; I am still studying. I try to write an article every week during my study. The above sections are my personal notes and online search. Due to the large number of learning tasks and insufficient personal language organization skills, if there is an

; } Age=NewAge;}//implementation of the Get method- (int) age{returnAge ;}- (void) study{NSLog (@"students at the age of%d are studying", age);//the use of age here can be accessed directly even when declaring member variables without writing @public (the object method can directly access member variables)}@endintMain () {Student*stu = [StudentNew]; //assigning a member variable inside an object by calling the Set method[Stu setage:-Ten]; [Stu Study]; //since there is no @public this is c