How to Get Int63n Type Random Number in Golang?

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

My Personal Notes

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