const   request   =   require('request');

request('https://www.google.com', (error, response, body) => {
 console.log('error: ', error);
 console.log('sratusCode: ', response   &&   response.statusCode);
 console.log(body);
});

// 選取所有 tag 為 'a' class 為 'board' 的元素（有一個以上，陣列回傳）
$('a.board')

// 從陣列拿某一個出來
$('a.board')[18]

// 選取所有 tag 為 'a' class 為 'board' 的元素
// 並尋找 class 為 'board-name' 的子元素（有一個以上，陣列回傳）
$('a.board').find('.board-name')

// 將某一個 class 為 'board-name' 的元素文字取出
$($('a.board').find('.board-name')[18]).text()

const cheerio = require('cheerio')
const $ = cheerio.load('<h2 class="title">Hello world</h2>')

$('h2.title').text('Hello there!')
$('h2').addClass('welcome')

console.log($.html())
//=> <h2 class="title welcome">Hello there!</h2>
//一樣存檔後用 node + 檔名執行看看

const   request   =   require('request');
const   cheerio   =   require('cheerio');
const   fs        =   require('fs');

let   HotBoardsJson   = [];
let   url   =   'https://www.ptt.cc'

request(url   +   '/bbs/index.html', (error, response, body) => {
 console.log('error: ', error);
 console.log('statusCode: ', response   &&   response.statusCode);

 // console.log('body: ', body);
 var   $   =   cheerio.load(body);
 boardArr   =   $('a.board');
    
 for (var i = 0; i < boardArr.length; i++) {
     boardName  =  $($(boardArr[i]).find('.board-name')).text();
     boardClass =  $($(boardArr[i]).find('.board-class')).text();
     boardLink  =  url + $(boardArr[i]).attr('href');
     HotBoardsJson.push({ boardName:   boardName, boardClass:   boardClass, boardLink:   boardLink })

     console.log(`${boardName}\n>> ${boardLink}\n>> 分類：${boardClass}\n`);
  }
  // 把爬下來的東西存起來法2
  fs.writeFile('HotBoards.json', JSON.stringify(HotBoardsJson), function (err) {
    if (err)
        console.log(err);
    else
        console.log('File '   +   'HotBoards.json'   +   'written!');
  })
  console.log('共 '   +   HotBoardsJson.length   +   ' 篇\\n');
});