struct method on value

package main

import (
    "fmt"
)

type Rect struct {
    width, length float64
}

func (rect Rect) area() float64 {
    return rect.width * rect.length
}

func main() {
    var rect = Rect{10, 20}

    fmt.Println("Width:", rect.width, "Length:", rect.length,
        "Area:", rect.area())
}