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 every time when 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 non-negative pseudo-random number in [0, n) of 63-bit integer n as an int64 type from the default source with the help of the Int63n() 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 Int63n() function. This method will panic if the value of n is <= 0.
Syntax:
func Int63n(n int64) int64
Let us discuss this concept with the help of the given examples:
Example 1:
// Golang program to illustrate how to // get int63n type random number package main import ( "fmt"
"math/rand"
) // Main function func main() { // Finding random numbers of int63n type
// Using Int63n() function
res_1 := rand .Int63n(7)
res_2 := rand .Int63n(3)
res_3 := rand .Int63n(1)
// Displaying the result
fmt.Println( "Random Number 1: " , res_1)
fmt.Println( "Random Number 2: " , res_2)
fmt.Println( "Random Number 3: " , res_3)
} |
Output:
Random Number 1: 5 Random Number 2: 1 Random Number 3: 0
Example 2:
// Golang program to illustrate how to // get int63n type random number package main import ( "fmt"
"math/rand"
) // Function func int63nrandom(value_1, value_2 int64) int64 { return value_1 + value_2 + rand .Int63n(4)
} // Main function func main() { // Getting result from Int63nrandom() function
res1 := int63nrandom(10, 3)
res2 := int63nrandom(430, 56)
res3 := int63nrandom(13, 500)
// Displaying results
fmt.Println( "Result 1: " , res1)
fmt.Println( "Result 2: " , res2)
fmt.Println( "Result 3: " , res3)
} |
Output:
Result 1: 15 Result 2: 489 Result 3: 514