Working with Go

Functions

Examples on how to use functions in Go.

Basic Function

An example of a basic function accepting one parameter and no return value. The parameter type must be specified in the function definition.

func Echo(s string) {
    fmt.Println(s)
}

Function with Return Value

Defining a function with a return value, you must specify the type for the return value.

func Say(s string) string {
    phrase := "Hello " + s
    return phrase
}

Named Returned Value

You can define a function with a named return variable. By using a named variable it initializes the variables. Also, by using a named variable you do not need to include the variable in return statement it will return the current value of the variable on return.

func Say(s string) (phrase string) {
    phrase = "Hello " + s
    return
}

Multiple Parameters

Function with multiple parameters and return values

func Divide(x, y float64) (float64, float64) {
    q := math.Trunc(x / y)
    r := math.Mod(x, y)
    return q, r
}

Function with multiple parameters and named return values. If the types are the same you can specify the type once at the end

func Divide2(x, y float64) (q, r float64) {
    q = math.Trunc(x / y)
    r = math.Mod(x, y)
    return
}

Variadic Parameters

A variadic function is a function that accepts an arbitrary number of arguments. Here is an example function accepting any number of ints. A slice is created out of the parameters passed in.

func Sum(x ...int) int {
    sum := 0
    for _, v := range x {
        sum += v
    }
    return sum
}

You can call the function with multiple parameters:

sum := Sum(1,3,5,7)
fmt.Println(sum)

You can also call using the spread operator:

nums := []int{1, 2, 3, 4, 5 }
sum := Sum(nums...)
fmt.Println(sum)