# 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
```

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