The grand module implements encapsulation and improvements for random number operations, achieving extremely high random number generation performance, and provides rich methods related to random numbers.

Usage:

import "github.com/gogf/gf/v2/util/grand"

API Documentation:

https://pkg.go.dev/github.com/gogf/gf/v2/util/grand

Common Methods:

func N(min, max int) int
func B(n int) []byte
func S(n int, symbols ...bool) string
func Str(s string, n int) string
func Intn(max int) int
func Digits(n int) string
func Letters(n int) string
func Meet(num, total int) bool
func MeetProb(prob float32) bool
func Perm(n int) []int
func Symbols(n int) string

Characters

Type    Characters
Numeric 0123456789
English abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
Special !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~

Random Integers

1. The Intn method returns a random integer greater than or equal to 0 and less than max, i.e., [0, max).
2. The N method returns a random integer between min and max, supports negative numbers, and includes boundaries, i.e., [min, max].

Random Strings

1. The B method is used to return a binary []byte data of specified length.
2. The S method is used to return a string of specified length consisting of numbers and characters. The second parameter symbols specifies whether the random string should include special characters.
3. The Str method is a more advanced method that selects a random string of specified length from a given character list and supports unicode characters, such as Chinese. For example, Str("中文123abc", 3) may return a random string like 1a文.
4. The Digits method returns a random numeric string of specified length.
5. The Letters method returns a random English string of specified length.
6. The Symbols method returns a random special character string of specified length.

Probability Calculation

1. Meet is used to specify a number num and a total total, often with num<=total, and randomly calculate whether the probability of num/total is met. For example, Meet(1, 100) will randomly calculate whether a one percent probability is met.
2. MeetProb is used to provide a probability float number prob, often with prob<=1.0, and randomly calculate whether this probability is met. For example, MeetProb(0.005) will randomly calculate whether a five per thousand probability is met.