GeezerVison

Functions are central in Go. We’ll learn about functions with a few different examples.

package main

import "fmt"

Here’s a function that takes two ints and returns their sum as an int.

func plus(a int, b int) int {

Go requires explicit returns, i.e. it won’t automatically return the value of the last expression.

    return a + b
}

When you have multiple consecutive parameters of the same type, you may omit the type name for the like-typed parameters up to the final parameter that declares the type.

func plusPlus(a, b, c int) int {
    return a + b + c
}

func main() {

Call a function just as you’d expect, with name(args).

    res := plus(1, 2)
    fmt.Println("1+2 =", res)

    res = plusPlus(1, 2, 3)
    fmt.Println("1+2+3 =", res)
}

$ go run functions.go 
1+2 = 3
1+2+3 = 6

There are several other features to Go functions. One is multiple return values, which we’ll look at next.