In Go, functions are first-class, typed programming elements. A declared function literal always has a type and a value (the defined function itself) and can optionally be bound to a named identifier. Because functions can be used as data, they can be assigned to variables or passed around as parameters of other functions.
Declaring a function in Go takes the general form illustrated in the following figure. This canonical form is used to declare named and anonymous functions.
The most common form of function definition in Go includes the function's assigned identifier in the function literal. To illustrate this, the following table shows the source code of several programs with definitions of named functions with different combinations of parameters and return types.
|
Code |
Description |
package main import (
"fmt"
"math"
)func printPi() {
fmt.Printf("printPi()
%v\n", math.Pi)
} func main() {
printPi() } ... |