18. Methods(方法)

18.1. Python

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2020/4/21 13:50
# filename: sample1.py
from __future__ import division
from math import sqrt


class Point(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def distance(self, other):
        return sqrt(self.x * other.x + self.y * other.y)


p1 = Point(1, 3)
p2 = Point(2, 4)
print(p1.distance(p2))  # 3.74165738677
print(p2.distance(p1))  # 3.74165738677

18.2. Go

package main

import (
    "fmt"
    "math"
)

type Point struct {
    x float64
    y float64
}

func (this Point) distance(other Point) float64 {
    return math.Sqrt(this.x*other.x + this.y*other.y)
}

// Dince结构会自动复制，
//最好将其作为指针传递。
func (this *Point) distance_better(other *Point) float64 {
    return math.Sqrt(this.x*other.x + this.y*other.y)
}

func main() {
    p1 := Point{
        x: 1,
        y: 3,
    }
    p2 := Point{
        x: 2,
        y: 4,
    }
    fmt.Println(p1.distance(p2))            //3.7416573867739413
    fmt.Println(p1.distance_better(&p2))    //3.7416573867739413

}