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# How to get int63 type random number in Go language?

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 the non-negative pseudo-random number of 63-bit integer as an int64 type from the default source with the help of the Int63() 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 Int63() function.

Syntax:

func Int63() int64

Let us discuss this concept with the help of the given examples:

Example 1:

 // Golang program to illustrate// how to get a random numberpackage main  import (    "fmt"    "math/rand")  // Main functionfunc main() {      // Finding random numbers of int63 type    // Using Int63() function    res_1 := rand.Int63()    res_2 := rand.Int63()    res_3 := rand.Int63()      // 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:  5577006791947779410
Random Number 2:  8674665223082153551
Random Number 3:  6129484611666145821

Example 2:

 // Golang program to illustrate// the use of the random numberspackage main  import (    "fmt"    "math/rand")  // Functionfunc int63random(value_1, value_2 int64) int64 {    return value_1 + value_2 + rand.Int63()  }  // Main functionfunc main() {      // Getting result from Int63random() function    res1 := int63random(10, 3)    res2 := int63random(430, 56)    res3 := int63random(13, 500)      // Displaying results    fmt.Println("Result 1: ", res1)    fmt.Println("Result 2: ", res2)    fmt.Println("Result 3: ", res3)}

Output:

Result 1:  5577006791947779423
Result 2:  8674665223082154037
Result 3:  6129484611666146334