In my poor opnion:
1. Golang is a programming language that not need a virtual machine, It
communicate directly with kernel, making use of all resource hardware
better than Java.
2. Golang uses goroutines that consume only 2k of memory instead of
2MB(minimun) of threads used in Java.
3. With Golang the dilema: "Write once run anywhere" is true, because you
can do a cross compile and run your program in differents platforms with
the same codebase.
4. Golang offering everything do you need, without necessity to install
any framework.
And many other qualities that I do not remember :)
Regards
Rodolfo Azevedo
Em seg, 28 de jan de 2019 às 21:16, Topget <topget1...@gmail.com> escreveu:
> It will be better if someone could give me the example(s) to show the
> advantage of Golang (vs Java). Thanks.
>
> 在 2019年1月25日星期五 UTC+8上午10:21:14，Topget写道：
>>
>> I have tested several simple functions with Golang and Java. To my
>> surprise, Java sometimes is faster than Golang（especially in recursive
>> function and some function in standard library such as math/rand.Rand）. I
>> wonder why. Here is some code I used for test and the result.
>>
>> Golang code:
>>
>> package main
>>
>> import (
>> "fmt"
>> "math/rand"
>> "time"
>> )
>>
>> func calPi(pointCount int) float64 {
>> inCircleCount := 0
>>
>> var x, y float64
>> var Pi float64
>>
>> for i := 0; i < pointCount; i++ {
>> x = rand.Float64()
>> y = rand.Float64()
>>
>> if x*x+y*y < 1 {
>> inCircleCount++
>> }
>> }
>>
>> Pi = (4.0 * float64(inCircleCount)) / float64(pointCount)
>>
>> return Pi
>> }
>>
>> func fibonacci(c int64) int64 {
>> if c < 2 {
>> return c
>> }
>>
>> return fibonacci(c-2) + fibonacci(c-1)
>> }
>>
>> func main() {
>> rand.Seed(time.Now().Unix()) // 初始化随机数
>>
>> fmt.Printf("Test 1\n")
>>
>> startTime := time.Now()
>>
>> result := 0.0
>>
>> for i := 0.0; i < 1000000000; i = i + 1 {
>> result += i * i
>> }
>>
>> endTime := time.Now()
>>
>> fmt.Printf("Result: %v\n", result)
>>
>> fmt.Printf("Duration: %v\n", endTime.Sub(startTime))
>>
>> fmt.Printf("Test 2\n")
>>
>> startTime = time.Now()
>>
>> resultInt := fibonacci(50)
>>
>> endTime = time.Now()
>>
>> fmt.Printf("Result: %v\n", resultInt)
>>
>> fmt.Printf("Duration: %v\n", endTime.Sub(startTime))
>>
>> fmt.Printf("Test 3\n")
>>
>> startTime = time.Now()
>>
>> result = 0.0
>>
>> for i := 0.0; i < 100000000; i = i + 1 {
>> result += rand.Float64()
>> }
>>
>> endTime = time.Now()
>>
>> fmt.Printf("Result: %v\n", result)
>>
>> fmt.Printf("Duration: %v\n s", endTime.Sub(startTime))
>>
>> fmt.Printf("Test 4\n")
>>
>> startTime = time.Now()
>>
>> result = calPi(100000000)
>>
>> endTime = time.Now()
>>
>> fmt.Printf("Result: %v\n", result)
>>
>> fmt.Printf("Duration: %v s\n", endTime.Sub(startTime))
>>
>> }
>>
>>
>> the result:
>>
>> Test 1
>> Result: 3.333333328333552e+26
>> Duration: 1.449212507s
>> Test 2
>> Result: 12586269025
>> Duration: 1m31.645050682s
>> Test 3
>> Result: 4.999483069673434e+07
>> Duration: 2.534121566s
>> sTest 4
>> Result: 3.14147056
>> Duration: 5.036491495s s
>>
>> Java code:
>>
>> public class Performance {
>>
>> public static double calPi(int pointCount) {
>> int inCircleCount = 0;
>>
>> double x, y;
>> double Pi;
>>
>> for (int i = 0; i < pointCount; i++) {
>> x = Math.random();
>> y = Math.random();
>>
>> if (x * x + y * y < 1) {
>> inCircleCount++;
>> }
>> }
>>
>> Pi = (4.0 * inCircleCount) / pointCount;
>>
>> return Pi;
>> }
>>
>> public static double cal(double a, double b, double c) {
>> return a * b / (c + 1) + a;
>> }
>>
>> public static long fibonacci(long c) {
>> if (c < 2)
>> return c;
>> return fibonacci(c - 2) + fibonacci(c - 1);
>> }
>>
>> public static void main(String[] args) {
>>
>> System.out.println("Test 1");
>>
>> long startTime = System.currentTimeMillis();
>>
>> double result = 0.0;
>>
>> for (double i = 0.0; i < 1000000000; i = i + 1) {
>> result += i * i;
>> }
>>
>> long endTime = System.currentTimeMillis();
>>
>> float duration = (float) (endTime - startTime) / 1000;
>>
>> System.out.println("Result: " + result);
>> System.out.println("Duration: " + duration + " s");
>>
>> System.out.println("Test 2");
>>
>> startTime = System.currentTimeMillis();
>>
>> long resultInt = fibonacci(50);
>>
>> endTime = System.currentTimeMillis();
>>
>> duration = (float) (endTime - startTime) / 1000;
>>
>> System.out.println("Result: " + resultInt);
>> System.out.println("Duration: " + duration + " s");
>>
>> System.out.println("Test 3");
>>
>> startTime = System.currentTimeMillis();
>>
>> result = 0.0;
>>
>> for (double i = 0; i < 100000000; i = i + 1) {
>> result += Math.random();
>> }
>>
>> endTime = System.currentTimeMillis();
>>
>> duration = (float) (endTime - startTime) / 1000;
>>
>> System.out.println("Result: " + result);
>> System.out.println("Duration: " + duration + " s");
>>
>> System.out.println("Test 4");
>>
>> startTime = System.currentTimeMillis();
>>
>> result = calPi(100000000);
>>
>> endTime = System.currentTimeMillis();
>>
>> duration = (float) (endTime - startTime) / 1000;
>>
>> System.out.println("Result: " + result);
>> System.out.println("Duration: " + duration + " s");
>>
>> }
>> }
>>
>>
>> result:
>>
>> Test 1
>> Result: 3.333333328333552E26
>> Duration: 2.948 s
>> Test 2
>> Result: 12586269025
>> Duration: 60.816 s
>> Test 3
>> Result: 4.9999087237930864E7
>> Duration: 2.448 s
>> Test 4
>> Result: 3.14147284
>> Duration: 4.786 s
>>
>>
>> The difference of Test 2 results really shocked me!
>>
>> --
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