Final review (Day2)

2022.6.21DAY583

        Today I saw 《 data structure 》 Part of the stack and queue , Stacks and queues are linear tables , The difference between them is ： A stack is a linear table that can only be inserted and deleted at the end of a table . Queues are only allowed to insert at one end , A linear table with deletion at the other end . Then there are the stack in and stack out operations .《 Automatic control principle 》 I saw the drawing of logarithmic frequency characteristic curve , The characteristic curve of a control system can be obtained by the superposition of logarithmic frequency characteristic curves of typical links in series . Draw steps ：1. The open-loop transfer function of the system is transformed into the product of each typical link （ Series connection ） In the form of .2 If there is inertia in the system , Concussion link , First order differential link , Or second-order differential link , You need to make sure Turning frequency , Marked on W On the shaft .3. The initial value of the asymptotic logarithmic amplitude frequency characteristic curve is determined according to the proportional link and integral link of the system .

        Today is the second day of Review , in general , The review time is tight . Didn't take a nap , Only completed the daily review task 40%, Catch up with some progress tomorrow ！

read ：《 The underlying logic 》12% 《 Big talk data structure 》93 page

English ：  read "  the three languages  "   rage n Great anger    frogs n frog

motion ：2 km

package Phone;

public class Phone {
    public void call(String name){
        System.out.println(" to "+name+" Make a phone call ");
    }
}

package Phone;

public class NewPhone extends Phone{
   // public void call(String name)
    @Override
/*
 Method rewriting 
*/
   public void call(String name){
       System.out.println(" Turn on video function ");
       System.out.println(" to "+name+" Make a phone call ");
   }
}

package Phone;

import Phone.Phone;

public class PhoneDemo {
    public static void main(String[] args) {
        Phone p=new Phone();
        p.call(" Brigitte Lin ");
        NewPhone np=new NewPhone();
        np.call(" Brigitte Lin ");
    }
}

Method rewriting

As like as two peas, the same method declaration is found in the subclass.

Application of method rewriting

When a child class needs the function of a parent class , When the function subject subclass has its own content , You can override the methods of the parent class , such , It follows the function of the parent class , It also defines the specific content of the subclass .

@Override

• It's a comment
• It can help us check the correctness of the method declaration of the rewriting method .