Go language provides inbuilt support for generating random numbers of the specified type with the help of a math/rand package. This package implements pseudo-random number generators. These random numbers are generated by a source and this source produces a deterministic sequence of values whenever the program run. And if you want to random numbers for security-sensitive work, then use the crypto/rand package.
You are allowed to generate a slice of n ints which contains a non-negative pseudo-random permutation of the integers [0, n) from the default source with the help of the Perm() Function provided by the math/rand package. So, you need to add a math/rand package in your program with the help of the import keyword to access the Perm() function.
Syntax:
func Perm(n int) []int
Let us discuss this concept with the help of the given examples:
Example 1:
// Golang program to illustrate // how to get a random number package main import ( "fmt"
"math/rand"
) // Main function func main() { // Getting the random permutation
// of integers in the form of slice
// Using Perm() function
for _, res_1 := range rand .Perm(4) {
// Displaying the result
fmt.Println( "Slice 1 Element: " , res_1)
}
for _, res_2 := range rand .Perm(3) {
// Displaying the result
fmt.Println( "Slice 2 Element: " , res_2)
}
} |
Output:
Slice 1 Element: 0 Slice 1 Element: 1 Slice 1 Element: 2 Slice 1 Element: 3 Slice 2 Element: 1 Slice 2 Element: 2 Slice 2 Element: 0
Example 2:
// Golang program to illustrate // how to get a random permutation // of integers package main import ( "fmt"
"math/rand"
) // Main function func main() { // Getting the random permutation
// of integers in the form of slice
// Using Perm() function
res_1 := rand .Perm(5)
res_2 := rand .Perm(7)
fmt.Println( "Slice 1: " , res_1)
// Finding the length of the slice
fmt.Println( "Length of Slice 1: " , len(res_1))
// Finding the capacity of the slice
fmt.Println( "Capacity of Slice 1: " , cap(res_1))
fmt.Println( "Slice 2: " , res_2)
// Finding the length of the slice
fmt.Println( "Length of Slice 2: " , len(res_2))
// Finding the capacity of the slice
fmt.Println( "Capacity of Slice 2: " , cap(res_2))
} |
Output:
Slice 1: [0 4 2 3 1] Length of Slice 1: 5 Capacity of Slice 1: 5 Slice 2: [4 1 5 0 3 2 6] Length of Slice 2: 7 Capacity of Slice 2: 7