Interviewer: is it acceptable to transfer to go?

1、 introduction

Hello everyone , I'm yinbelle , Recently, there are many little friends who are experiencing internships 、 Interview of Qiu Zhao , I believe that many partners will meet the company they are interviewing 、 The programming language used by the Department is different from what I am familiar with , Many friends sent me private messages saying that now many interviewers will ask whether they can accept transfer Go Language , Ask my advice , Hey, isn't this a coincidence , Here comes the video material , Friends who know me well know that I graduated this year , Bytes removed by calibration , I haven't been in contact with business during the period of graduation and the past few weeks of entry , Are familiar with Go Language and related frameworks .

Then I want to share my card in this video Go Feelings . Because the projects done in school, including summer internship in Alibaba, are used Java, So subjectively, it will be more with Java Look at Go, At the same time, I will try to make it easy to understand , Let the little friends who just came into contact with programming have a general understanding .

2、Go First experience

2.1 Go The origin of

Let me give you a brief introduction Go The origin of language ,Go Language （Golang） origin 2007 year , It's an internal project of Google , And in 2009 Officially released in ,java I remember it was 1995 Published in . Design Go Its original intention is to make its compilation speed comparable to C or C++, The syntax is simpler and safer , Native supports concurrency .

① This one in the middle is Rob Pike,Go Head of language project , Bell LABS Unix Team members , Participating projects include Plan 9,Inferno Operating system and Limbo programing language ;

② On the left is RobertGriesemer, Participation in development JavaHotSpot virtual machine

③ This one on the right is Ken Thompson, Bell LABS Unix Team members ,C Language 、Unix and Plan 9 One of the founders of , And Rob Pike Jointly developed UTF-8 Character set specification

2.2 Go Learning experience

Let's start with the results , Overall, I feel pretty good , After all Go It's developing very fast , Especially the new version 1.18 Generics are also added . When I write here, I suddenly find myself really lucky , Learn at school Java It's time to have springboot Family bucket , You don't have to suffer when doing projects JSP The devastation of ;Go After many iterations, updates and some gin、gorm Easy to use framework blessing , Package management tools are also built in mod, Don't write disgusting code and configuration . I think the maturity of the framework is very friendly for new people who come into contact with a language , You can directly write some small projects to practice your hand , Next, let's talk about our feelings from a few points , First, share some intuitive feelings .

1、 Normative
Specifications are greater than conventions , That is to say, if I don't make an appointment with you , You have to follow this set of rules , If you don't compile according to the specification, you can't pass .

• Such as exported packages and defined variables , If it is not used, an error will be reported , Can't accommodate redundant statements .
• And naming conventions , Can the defined variable be externally referenced ,Java Through the keyword public perhaps private To decide ,Go Is distinguished by the case of variables
• Go Function overloading is not allowed on , Must have unique names for methods and functions .Java Allow function overloading .

2、 Speed , Factorials are used to test performance on the Internet , You can see after running on this machine , In the case of a single thread

in addition ,Go There is also a more powerful feature in the native support for high concurrency , In the concurrent scenario Go It adopts a collaborative process with smaller resource granularity , I also ran a few hours demo To test performance , Find out Go Performance ratio of Java There is no very significant enhancement , I'm looking for the answer on the Internet , Finally found this sentence ：
Go The level of performance is related to the programming ability of programmers

package main

import (
	"fmt"
	"math/big"
	"strconv"
	"time"
)

func main(){
    

	allInputs := [5]int64{
    10000, 50000, 100000, 500000, 1000000}

	var i int = 1
	for i=0;i<len(allInputs);i++ {
    

		var before = GetTimeStamp()

		var factorial *big.Int = big.NewInt(1)
		var j int64 = 1
		for j=1; j<=allInputs[i]; j++ {
    
			factorial = factorial.Mul(factorial,big.NewInt(j))
		}
		var after = GetTimeStamp()
		var elapsedTime = after - before
		gap,_ := strconv.ParseFloat(fmt.Sprintf("%.2f", float64(elapsedTime)/float64(1000)), 64)
		fmt.Printf("%v  The factorial time is %v second \n",allInputs[i],gap)
	}
}

func GetTimeStamp() int64 {
    
	//  Get the millisecond timestamp 
	return time.Now().UnixNano() / int64(time.Millisecond)
}

import java.math.BigDecimal;
import java.math.BigInteger;

class TestDemo {
    
    public static void main(String []args) {
    
        int[] allInputs = new int[]{
    10000, 50000, 100000, 500000, 1000000};
        for (int i = 0; i < allInputs.length; i++) {
    
            BigInteger number = BigInteger.valueOf(allInputs[i]);
            BigInteger result = BigInteger.valueOf(1);
            long before = System.currentTimeMillis();
            for (int j = 1; j <= allInputs[i]; j++) {
    
                result = result.multiply(BigInteger.valueOf(j));
            }
            long after = System.currentTimeMillis();
            System.out.println(allInputs[i] + " The time taken for factorial " +
                    new BigDecimal((float)(after - before)/1000).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue()+" second ");
        }
    }}

3、 object-oriented
I try to share clearly , Here and Java The difference is big , Three basic characteristics of object-oriented ： encapsulation 、 Inherit 、 polymorphic .
One thing that needs to be clear is ,Go Not an object-oriented language , But it does not prevent it from having object-oriented features .

• The first is encapsulation ,Go There is no concept of a class , Use structure to package , And there are only attributes in the structure , Methods and structures are separate , You can see that the method is bound to the structure ,Go There are few references in , It's usually The pointer . Maybe the author wants to give users of structures more flexibility . That is, even if you are not the author of the structure , You are also free to add new “ Member method ”.
  
• Inherit , stay Java We have used the customary inheritance method in Go None of them ,Go Inheritance is realized through combination , Let a structure A Contains a structure B, So as to achieve A To inherit B Characteristics of .
  
• Polymorphism usually means , Subclass objects can be used wherever parent objects are used , Simply speaking , Polymorphism means that variables of the parent type can refer to objects of the child type . for instance , There are many kinds of fruits , a mandarin orange 、 Banana , Now I want a fruit （ Don't specify which fruit you want ）, Give me an orange or banana ok Of , This is that variables of the parent type can refer to objects of the child type .Java Allow polymorphism by default , and Go But there was no ,Go Polymorphism in is through Interface Realized .

package main

import "fmt"

type Code interface {
    
	introduce()
}

type Java struct {
    
	name string
}

func (javaTest Java) introduce()  {
    
	fmt.Println("this is java")
}

type Go struct {
    
	name string
}
func (goTest Go) introduce()  {
    
	fmt.Println("this is go")
}
func introduce(code Code)  {
    
	code.introduce()
}
func main() {
    
	introduce(&Java{
    })
	introduce(&Go{
    })
}

We can see that when we add a function to the system , Not by modifying the code , But by adding code , So that is Opening and closing principle The core idea of .Go Pass through interface To provide an abstract interface , So as to achieve high cohesion , Low coupling .

3、 Video plan ：

I found that many friends are right Go Language is more interesting , But under the pressure of work or study, it is not necessary for the time being Go Language , Want to know, but was persuaded by dozens of hours of tutorial videos , and Go Language is currently in the stage of rapid development , Get faster , The syntax in many videos is no longer applicable .

So I'm going to put Go Divided into primary 、 senior 、 Three parts of actual combat , With Java Turn around and make a series of sharing videos in your learning process , Each update will put the video on the corresponding blog , The content should be concise and easy to understand , You can get started by video , The links to supplementary documents in the difficult part ensure that everyone can have an in-depth understanding on the premise of energy , The video will not change, but the document can be updated , If there is any change, I will update my blog in time .

There is a gift I prepared for you on my blog （ Learning materials and learning tools ）, Just take it yourself , I will also send updates and updates to official account as soon as possible , The official account also has an internal link for you to prepare big factories , Interested partners can easily pay attention .

In addition, my team in the company , There is a step-by-step plan every week , That is to say, we often use but dig deep technology stacks , For example, last issue talked about mysql, The index 、buffer、 Clusters and other parts are talked about deeply . After that, I will also pick some wonderful parts to blog + Share the video with you , I hope you guys can pay attention , It is convenient to push it to you in a timely manner .

What theme videos do you want to see? You can leave a message and interact at the bottom of the video , I will put the blog link of each video in the introduction , It is convenient for everyone to check .

4、 Question answering ：

How should we treat it Go Language , I have a little opinion , That's it “ Refuse to eat the old technology , Always learn new technology and keep yourself ”, No matter what technology stack you are currently using , It's always right to have the opportunity to learn more . hold Go As my second programming language, I think it's a very good decision .

But if you are a school recruit who is looking for a job , I suggest to Java perhaps C++ Mainly , Why? , Because now the situation is Go Jobs are generally in big factories , Large factories have many application scenarios and have the capital to try and make mistakes , Small factories still aim at stable operation , Besides, even if you interview Go Your position is also available Java perhaps C++ Knowledge points ,Go Language can be regarded as a bonus for you . Big factories usually don't pick technology stacks when recruiting fresh students , Just go deep into one , And have good basic knowledge and thinking , Just come in and cultivate again .

Okay , That's all about this video , If you like this video , Remember to pay attention to one button three times