ryanlid

void main() {
  Human jenny = Human(startingHeight: 15);
  print(jenny.height);

  Human jemes = Human(startingHeight: 20);
  print(jemes.height);

  jemes.talk("hello");
}

ryanlid

void main() {
  Human jenny = Human(15, 40);
  print(jenny.height);

  Human jemes = Human(110, 10);
  print(jemes.height);
  print(jemes.weight);

  jemes.talk("hello");
}

ryanlid

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Screen1(),
    );

ryanlid

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      initialRoute: "/",
      routes: {

ryanlid

import 'dart:io';

void main() {
  performTask();
}

void performTask() async {
  task1();
  String task2result = await task2();
  task3(task2result);

ryanlid

void main() {
  Car myCar = Car();
  print(myCar.numberOfSeat);
  myCar.drive();
  
  ElectriCar myTesla = ElectriCar();
  myTesla.drive();
  print(myTesla.batteryLevel);
  
}

ryanlid

const http = require("http");
const https = require("https");
const fs = require("fs");
const express = require("express");
const app = express();

// http server
const http_server = http.createServer(app);
http_server.listen(80, "0.0.0.0");
const options = {

ryanlid

function ajax(method, url, data) {
  var request = new XMLHttpRequest();
  return new Promise(function (resolve, reject) {
    request.onreadystatechange = function () {
      if (request.readyState === 4) {
        if (request.status === 200) {
          resolve(request.responseText);
        } else {
          reject(reject(reject.status));
        }

ryanlid

const koa = require("koa");
const app = new koa();
app.use(async (ctx, next) => {
  let stime = new Date().getTime();
  await next();
  let etime = new Date().getTime();
  ctx.response.type = "text/html";
  ctx.response.body = "<h1>Hello World</h1>";
  console.log(`请求地址：${ctx.path},响应时间：${etime - stime}`);
});

ryanlid

const koa = require("koa");
const app = new koa();
const bodyParser = require("koa-bodyparser");
app.use(bodyParser());

app.use(async ctx => {
  if (ctx.url === "/" && ctx.method === "GET") {
    ctx.type = "html";
    let html = `
    <h1>登录</h1>