Programmer Think

⭐ preface ⭐ This article introduces classes and objects in Java. 🎉 Welcome to pay attention 🔎 give the thumbs-up 👍 Collection ⭐ Leave a message 📝 🔑GitHub Java warehouse, welcome to visit🔑 📝The blogger's note link is updated at the first time📝 🌲 class Classes are templates or blueprints for constructing objects. The proc ...

1. Object oriented overview Process oriented: specific, step-by-step, suitable for dealing with simple problems. **Object oriented: * * is abstract. To solve problems, first classify them and think about the divided classes separately. It is suitable for dealing with complex problems and multi person cooperation problems. However, the det ...

Application of abstract classes: design patterns of template classes // Application of abstract classes: design patterns of template methods public class TemplateTest { public static void main(String[] args) { Template t = new SubTemplate(); t.spendTime(); } } abstract class Template{ // Calculate the time spent exe ...

JAVA basic learning method Java's main memory space When the code is placed in the method area to execute the main file first, when the main method is executed, the memory space required by the method is allocated in the stack, which is a data structure Stack data structure Stack data structure: stack What is a data structure? The ...

Implementation of multithreading 1. Inherit Thread class     (1) define a class to inherit Thread and override the run() method;     (2) create subclass objects of Thread class;     (3) call start() to start a new thread. //The main thread and the custom thread execute concurrently public class th ...

Polymorphism of characteristics 1, Concept The image point is that the same behavior is performed by different people or things 2, Realization conditions   It must be under the inheritance systemDerived classes must override methods in the base classThe overridden method must be called through a reference to the base class 3, ...

1, Package 1. In order to better manage classes, collect multiple classes into a group and become a software package Package is the embodiment of the encapsulation mechanism of classes and interfaces. It is a better management of classes or interfacesClasses with the same name are not allowed in the same package, but they can exist in differe ...

1 Map interface Map and Collection have no inheritance relationship The Map collection stores data in the form of key and value: key value pairs Both key and value are reference data types. Both key and value are memory addresses of storage objects. Key plays a leading role, and value is an accessory of key. Common methods in Map interf ...