golang語言漸入佳境[30]-rand-package

package main

import (
	"fmt"
	"math/rand"
	"time"
)

func main() {
	randTest()

	randAnswer()
}

func randTest() {
	//1、通過默認的隨機數(shù)種子獲取隨機數(shù).
	//系統(tǒng)默認的rand對象，隨機種子默認都是1
	fmt.Println(rand.Int())
	fmt.Println(rand.Intn(50))
	fmt.Println(rand.Float64())

	//	2、動態(tài)隨機種子，生成隨機資源，實例化成隨機對象，通過隨機對象獲取隨機數(shù)
	s1 := rand.NewSource(time.Now().UnixNano())
	r1 := rand.New(s1)
	randnum := r1.Intn(10)
	fmt.Println(randnum)

	//3、簡寫形式：動態(tài)種子來獲取隨機數(shù)
	//	[0,10]
	rand.Seed(time.Now().UnixNano())
	fmt.Println(rand.Intn(10))

	fmt.Println(rand.Float64())

	//[5,11]
	num := rand.Intn(7) + 5
	fmt.Println(num)
}

func randAnswer() {
	answers := []string{
		"It is certain",
		"It is decidedly so",
		"Without a doubt",
		"Yes definitely",
		"You may rely on it",
		"As I see it yes",
		"Most likely",
		"Outlook good",
		"Yes",
		"Signs point to yes",
		"Reply hazy try again",
		"Ask again later",
		"Better not tell you now",
		"Cannot predict now",
		"Concentrate and ask again",
		"Don't count on it",
		"My reply is no",
		"My sources say no",
		"Outlook not so good",
		"Very doubtful",
	}
	rand.Seed(time.Now().UnixNano())
	randnum := rand.Intn(len(answers))
	fmt.Println("隨機回答", answers[randnum])
}