Go Functions

Go functions, multiple return values, and variadic parameters
Tags:

Functions

Use func to define a function and return to specify its return value.

package main

import "fmt"

func add(x int, y int) int {
	return x + y
}

func main() {
	fmt.Println(add(5, 3)) // => 8
}

Output:

8

Multiple return values

A function can return multiple values. Group the return types with parentheses.

func addMinus(x int, y int) (int, int) {
	return x + y, x - y
}

func main() {
	add, min := addMinus(8, 5)
	fmt.Println(add, min)
}

Output:

13 3

Use the blank identifier _ to ignore an unnecessary return value.

_, y := funcA()

Variadic parameters

Use ... to define a variadic parameter.

package main

import "fmt"

func funcA(a int, b ...int) {
	fmt.Printf("a=%d\n", a)
	for i, num := range b {
		fmt.Printf("b[%d]=%d\n", i, num)
	}
}

func main() {
	funcA(1, 2, 3, 4, 5)
}

Output:

a=1
b[0]=2
b[1]=3
b[2]=4
b[3]=5