A Tour of Go Function values

Functions are values too.

在函数式语言中中函数都是变量，比如在javascript中

package main 

import (
    "fmt"
    "math"
)

func main() {
    hypot := func(x,y float64) float64 {
        return math.Sqrt(x*x + y*y)
    }
    fmt.Println(hypot(3, 4))
}