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object-oriented I Construction method 1. Question: we have never written a constructor in the class before, but we can still create objects. Where is the constructor used? be careful: 1,If we don't give a construction method, JVM Automatically provides a construction of an empty method body without parameters method 2,If we give a con ...

static keyword Features of static keyword: 1) Loads as the class loads 2) Priority object exists: It cannot coexist with this (this: represents the address value reference of the current class object) When the object does not have new, the member currently modified by static has memory 3) Statically modified Can be shared by multiple obj ...

Tip: the following is the main content of this article, and the Java series learning will be continuously updated (1) Basic concepts   abstract class: a superset of ordinary classes, but with more abstract methods than ordinary classes. For a class decorated with the abstract keyword, an abstract class cannot instantiate an obj ...

1. Preface Preliminary knowledge for reading this article: Constructor, copy construct, copy constructClass access qualifierClass instantiationthis pointer Reference return catalog: Operator overloading Friend function, friend class, inner classDate class After we quickly get started with C + +, the first thing to bear the brunt is to lear ...

1 static We sometimes hope that no matter whether objects are generated or how many objects are generated, there is only one copy of some specific data in the memory space. For example, all Chinese have a country name, and each Chinese shares the country name. It is not necessary to assign a variable representing the country name in each Chine ...

Strategy mode II DownsampleStrategy Package path: com bumptech. glide. load. resource. bitmap. DownsampleStrategy Indicates the algorithm used when down sampling the image. DownsampleStrategy does not provide any guarantee about the output size. The behavior will vary, depending on the strategy used by the ResourceDecoder and the Android ver ...

Structures and classes definition Place multiple objects together as a whole //definition struct str { int x; double y; }; //statement struct str; //Only the declaration only knows that str is a struct, but it is not known internally. At this time, str is incomplete type //However, str* mystr can be defined; The pointer size of all ...

I polymorphic 1. Class polymorphism Requirements: Demand: teachers go to work by bike Analysis: teachers, bicycles Demand upgrade / iteration: Bicycle - > car Steps: 1. Create a Car class and write start and stop 2. Write open and close based on the original Teacher class Note: violation of OCP principles OCP - opening an ...

Java object oriented learning Source of learning materials: Alibaba cloud University Java object-oriented programming Magic Music Technology Software School Other notes will be updated in this note: Java learning notes 1. Class and object 1.1 introduction to object oriented Encapsulation: internal operations are not visible to the outs ...

object-oriented inherit Usage scenario: if multiple similar classes have the same attributes and methods, you can extract the same attributes and methods from the parent class Benefits: reduced code redundancy Deep inheritance: When creating a subclass object, will the parent class constructor be called? meeting If you create a s ...