Difficulty with variadic functions [closed] - go

Question

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 3 years ago.
Improve this question
From An Introduction to Programming in Go, page 91, Exercise Question no 4, Topic: Functions:
Write a function with one variadic parameter that finds the greatest number in a list of numbers?
So far I had written this code but it is showing errors
package main
import (
"fmt"
)
func findMaximum(args ...[]int) []int {
max := args[0]
for _, v := range args {
if v > []args {
max = v
}
}
return args
}
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
fmt.Println(findMaximum(x))
}
I had taken reference from this Program
(Page, 75, Question No. - 4, Topic: Arrays, Slices and Maps)
Write a program that finds the smallest number
in this list:
x := []int{
48,96,86,68,
57,82,63,70,
37,34,83,27,
19,97, 9,17,
}
This is the program I had written to solve this Question
package main
import "fmt"
func main() {
arr := []uint{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
min := arr[0] // assume first value is smallest
for _, value := range arr {
if value < min {
min = value // found another value, replace previous value of min
}
}
fmt.Println("The smallest value is : ", min)
}
This Question Program is running but the First one is not I don't know why.

Answer 1

In mathematics and in computer programming, a variadic function is a
function of indefinite arity, i.e., one which accepts a variable
number of arguments.
Source: Wikipedia
Your function signature is slightly incorrect.
func findMaximum(args ...[]int) []int
This indicates that findMaximum takes in a variable number of int slices as arguments and returns an int slice. The problem that you're trying to solve is asking to take in a variable number of int arguments and return a singular int which is the largest in the set provided.
Calling your function would look something like this:
largest := findMaximum([]int{1, 2, 3}, []int{4, 5, 6}, []int{7, 8, 9})
In this case, largest would be of type []int indicating that the function returned multiple int values in the form of a slice. This wouldn't make sense, since there should only be one largest value (assuming no duplicates).
You're wanting a function signature that looks like this:
func findMaximum(args ...int) int
Calling this function would look like this:
largest := findMaximum(1, 2, 3, 4, 5, 6, 7, 8, 9)
...or if you had your numbers in a slice:
nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
largest := findMaximum(nums...)
In this case, largest would be of type int, which is the correct return value you're looking for in this problem.
(Go Playground)
Good luck!

Answer 2

If you run your code through https://play.golang.org/ you will see a couple of syntax errors. Below is the correct version which finds max in a slice.
As you can note you had extra ... in the slice argument call.
package main
import (
"fmt"
)
func findMaximum(args []int) int {
max := args[0]
for _, v := range args {
if v > max{
max = v
}
}
return max
}
func main() {
x := []int{
48, 96, 86, 68,
57, 82, 63, 70,
37, 34, 83, 27,
19, 97, 9, 17,
}
fmt.Println(findMaximum(x))
}