Golang : Variadic function arguments sanity check example




Problem:

Golang is cool and you love to use variadic function frequently. You have a variadic function such as a totalizer functions that accept any number of arguments. Such as

 func variadicFunction(arguments ...int) {}

Somehow a user of your program or variadic function managed to sneak in a null/nil or empty argument. This caused your variadic function to go crazy.

How to prevent this from happening?

Solution:

You want to perform sanity check on your users and their input arguments first before processing further. For example :

 package main

 import "fmt"

 func totalizer(values ...int) {

  if values == nil {
 fmt.Println("boom! - no number in arguments")
 //panic("kaboom") -- if you choose to kill the program

  } else {

 fmt.Print(values, " ")
 total := 0
 for _, value := range values {
 total += value
 }
 fmt.Println(total)
  }
 }

 func main() {

  totalizer(2)
  totalizer(1, 2, 3)
  totalizer()

 }

Output:

[2] 2

[1 2 3] 6

boom! - no values given in arguments

Happy coding and don't let your user bomb your program!





By Adam Ng

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