Use rand in golang to generate random non-repeating numbers

In Golang, there are two packages that provide rand, namely "math/rand" and "crypto/rand", corresponding to two application scenarios.

1. The "math/rand" package implements a pseudo-random number generator. That is, generating integers and floating point types.

2. The "crypto/rand" package implements a more secure random number generator for encryption and decryption.

Use rand in golang to generate random non-repeating numbers:

package test

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

//生成若干个不重复的随机数
func RandomTestBase() {
	//测试5次
	for i := 0; i < 5; i++ {
		nums := generateRandomNumber(10, 30, 10)
		fmt.Println(nums)
	}
}

//生成count个[start,end)结束的不重复的随机数
func generateRandomNumber(start int, end int, count int) []int {
	//范围检查
	if end < start || (end-start) < count {
		return nil
	}

	//存放结果的slice
	nums := make([]int, 0)
	//随机数生成器，加入时间戳保证每次生成的随机数不一样
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for len(nums) < count {
		//生成随机数
		num := r.Intn((end - start)) + start

		//查重
		exist := false
		for _, v := range nums {
			if v == num {
				exist = true
				break
			}
		}

		if !exist {
			nums = append(nums, num)
		}
	}

	return nums
}

Output result:

[12 20 18 19 21 28 15 13 11 10]

[28 15 12 10 20 18 16 24 27 17]

[25 28 29 19 21 12 16 13 11 15]

[27 20 19 23 18 13 21 24 12 26]

[19 10 27 18 28 12 22 14 16 26]

Recommended: golang tutorial

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