Soft exam summary

Hello everyone , I meet you again , I'm the king of the whole stack , I wish every programmer can learn more languages .

The review time for the soft exam starts from 3.24 Start 5.22 Start . 5.23 Embarked on the journey to Beijing to catch up with the examination .5.24 This day , It means that our soft exam study will enter the terminal , But there is no terminal for learning .

In the review of soft exam , No one enjoys the sense of abundance brought by knowledge , In order to leave a trace of review for yourself . I'd better summarize my review experience .

One 、 I'll pay you back when I get out

Soft test knowledge , It can be said that 60% or 70% of them have met in the study of self-study examination . Suppose that the students who took the self-examination of soy sauce , Think it over ~~~

Two 、 Soft test materials ：

1.J2SE video

Mainly about object-oriented thinking , This video is very important for our future study . Master the idea of object-oriented , The future is not difficult . But for soft Exam Review , We are mainly familiar with Java Some basic grammar of .

2. Hisai video

Hisai videos are the basic knowledge of soft exam . Including morning questions and afternoon questions . In the video, the teacher first interprets the knowledge points , Then we will talk about the real problems and exercises . When giving lectures , Teachers usually tell us some ideas for answering questions , This needs our reference . For video , As always, just ask to know , You don't have to cling to the knowledge points in the video . When watching the video, you will encounter a lot of people who understand , But it's all right , Just need to know in advance OK.

3. Design patterns （ Big talk && HeadFirst ）

It is suggested to watch the video while watching HeadFirst Design patterns , This book is very helpful for us to further study design patterns . However, there are many introductions and thinking problems of each design pattern in this book . So if you want to learn this book, you must set aside enough time . Big talk , I learned it before , Relatively simple .

4. Soft exam Tutorial

The soft test is not difficult , But the knowledge involved is very wide . All the questions can be answered in the textbook . So textbooks still need to be read carefully , Don't think you've seen the video of Cisse , You can return the book .

3、 ... and 、 Morning questions

Mainly through the real problem to consolidate . At the beginning , It is suggested to practice with several sets of older topics , Look for the feeling . Pay attention to when you finish the question , Be sure to go back and see the analysis , Back to the textbook . The distribution of the question types of the morning questions is very regular . So after finishing the question , Be sure to record where you lose more points . Another way is through group lectures . Group discussion , On the one hand, it deepened our understanding of knowledge , On the other hand, it also exercises our communication and expression skills .

Four 、 Afternoon question

1. Data flow diagram

Remember the principle ：

Parent graph and child graph balance ： The input / output data flow of a process in the parent graph must be the same in number and name as the input / output data flow of its child graph .

Data conservation ： Every processing must have input and output data ;

Remember the triple relationship ：

Entity —> machining machining —> machining machining —> file

2. database

Examination site ：E-R Figure complementary integrity and complementary relationship patterns

The relationship pattern is from E-R From the diagram . Compare relationship patterns with E-R chart , Suppose you find , But E-R Not in the picture , Explain that the corresponding entities need to be supplemented .

transformation ：

one-on-one ： Either end of the main code can be merged to another end

One to many ： take 1 The end master code is merged into N In the middle

Many to many ： Create a new relationship pattern , Take the main code at both ends + Self attribute

Ps: No matter how many, you can create a new connection model

3.UML chart

Usually it's relatively simple , The only difficulty is to find the class name . The first step in solving this kind of problem is to mark nouns according to the stem of the problem . The second step is to clarify the relationship between class diagrams , For example, dependence 、 relation 、 generalization 、 Combination and aggregation .

The nouns found by analyzing these relationships , Take a seat with the right number .

4. Algorithm

Remember the time and space complexity of algorithms often used , Even if the code can't be written , You can fill in oneortwo blanks in the back .

5. Design patterns

The problem of design pattern , These are the main test sites , abstract class 、 Abstract methods and interfaces ; Combine and aggregate the corresponding in the code ; The connotation of mode , That is to say client call .

A. Abstract method （abstract）VS Virtual method （Virtual) The difference between ： Abstract methods must be overridden in derived classes , Virtual methods can be written but not written . Abstract methods cannot declare method entities Virtual methods can Classes of abstract methods cannot be instantiated , Classes that include virtual methods can be instantiated ！

Be careful ：java It does not include （Virtual） Methodical

B. abstract class VS Interface differences ：

Same point ： You can't instantiate yourself , Be inherited ; Both methods and interface methods in abstract classes include method bodies

Difference ： multiple inheritance ：c# Abstract classes disagree , A class can only have one parent at most , Agree to inherit multiple interfaces Method ： Ordinary methods of abstract classes can have method bodies , Interface methods do not

Modifier ： Methods in interfaces cannot have access modifiers , Abstract methods in abstract classes are inherited , Need override rewrite

C. Compare aggregation and composition

Aggregate relationship ：

Code ：Public class GooseGroup{ Public Goose goose; Public GooseGroup(Goose goose){ this.goose = goose; } } Wild geese need wild geese , Pass wild geese as parameters to the constructor of wild geese , Wild geese can exist independently from wild geese . synthetic relation ：

Public class Bird { Public Wings wings; Public Bird(){ wings = new Wings(); // stay Bird Class , On initialization , Instantiate wings wing , They are generated at the same time } } stay Bird The constructor of includes Wing An instantiation of a class , Indicates that in instantiation Bird Before , First pair Wing instantiate , This ensures that the life cycle of the two classes is the same , That is, the assumption Bird Class no longer exists ,Wing Classes cannot exist alone . D.client call In the afternoon, the questions are on the exam client When called , In addition to understanding the basic connotation of design patterns , There are some main things you still need to know , such as , We are client When called , Usually instantiate its detailed subclasses . Abstract classes cannot be instantiated .

summary ：

The exam is not difficult , First of all, relax your mind . Be strategically contemptuous of the enemy , Pay attention to the enemy in wartime . When doing afternoon questions , We must start from the overall situation , Have a macro grasp of the topic , Be bold and careful .

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