Abstract learning

abstract Study

package com.oop.Demo07;

//abstract  abstract class ： class  extends： Single inheritance  （ Interfaces can inherit more 
public abstract class Action {
    
    // constraint 
    //abstract , Abstract method   Only the method name   There is no way to achieve 
    public abstract void doSomething();

    //1. You can't new This abstract class   It can only be implemented by subclasses ： constraint 
    //2. Ordinary methods can be written in abstract classes 
    //3. Abstract methods must be in abstract classes 
}
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package com.oop.Demo07;

public class A extends Action {
    

    @Override
    public void doSomething() {
    

    }
}