投稿時間:2022-07-31 12:16:20 RSSフィード2022-07-31 12:00 分まとめ(17件)

カテゴリー等	サイト名等	記事タイトル・トレンドワード等	リンクURL	頻出ワード・要約等/検索ボリューム	登録日
IT	ITmedia 総合記事一覧	[ITmedia ビジネスオンライン] “ナメクジ事件”で話題の「大阪王将」への保健所検査、抜き打ちじゃなかった　理由は？	https://www.itmedia.co.jp/business/articles/2207/31/news058.html	itmedia	2022-07-31 11:12:00
TECH	Techable（テッカブル）	ゲーム各社が展開するサブスクの違いを比較！レトロゲームから最新作まで各社のスタンスが明確に	https://techable.jp/archives/182661	applemusic	2022-07-31 02:00:27
AWS	lambdaタグが付けられた新着投稿 - Qiita	Microsoft365の監査ログを取得するLambda	https://qiita.com/a_b_/items/84d6ae3cf8a21b8b332c	lambda	2022-07-31 11:52:13
python	Pythonタグが付けられた新着投稿 - Qiita	二次方程式の解を求めるプログラム	https://qiita.com/ayakoro/items/6668f89d3f43488e3516	nteditboxgetbinteditboxge	2022-07-31 11:47:57
js	JavaScriptタグが付けられた新着投稿 - Qiita	「それ1メソッドでできますよ」	https://qiita.com/cp20/items/217b3e18be86ff7a9e38	reduce	2022-07-31 11:18:30
Linux	Ubuntuタグが付けられた新着投稿 - Qiita	ubuntu_studio を18.04に戻す	https://qiita.com/denki55/items/8daefda617f97676035f	plasma	2022-07-31 11:51:40
AWS	AWSタグが付けられた新着投稿 - Qiita	Microsoft365の監査ログを取得するLambda	https://qiita.com/a_b_/items/84d6ae3cf8a21b8b332c	lambda	2022-07-31 11:52:13
AWS	AWSタグが付けられた新着投稿 - Qiita	【AWS】新卒フロントエンジニアがAWS CLFに１ヶ月で合格した方法	https://qiita.com/D_suke/items/13113fcf11930dffe835	awsclf	2022-07-31 11:02:46
海外TECH	DEV Community	Singleton Pattern trong Javascript	https://dev.to/dylanvo28/singleton-pattern-1kba	Singleton Pattern trong JavascriptSingletons được hiểu làcác class cóthểđược khởi tạo một lần vàcóthểtruy cập trên toàn cục global Các class này cóthểchia sẽcác state trong toàn bộapp thìSingletons làmột thứtuyệt vời đểquản lýglobal state trong một app Vídụtôi sẽxây dựng một class Counter có a getInstance làphương thức trảvềvalue của của instancea getCount trảvềvalue hiện tại của biến counteran increment method làm tăng value của counter lên a decrement method làm giảm value của counter xuống let counter class Counter getInstance return this getCount return counter increment return counter decrement return counter Tuy nhiên class này không đáp ứng các yêu cầu cho một Singleton Một Singleton chỉcóthểđược khởi tạo một lần Hiện tại chúng ta cóthểtạo nhiều phiên bản của class Counterlet counter class Counter getInstance return this getCount return counter increment return counter decrement return counter const counter new Counter const counter new Counter console log counter getInstance counter getInstance falseBằng cách gọi method new lần tôi đặt obj tên counter vàcounter Value được trảvềbởi method getInstance của counter vàcounter nhưng chúng trảvềcác tham chiếu chúng không hoàn toàn bằng nhau Hãy đảm bảo rằng class Counter chỉcóthểtạo một lầnĐểđảm bảo rằng một instance cóthểđược tạo đólàtạo một biến variable được gọi làinstance Trong constructor của class Counter tôi cóthểset instance bằng một tham chiếu đến instance khi một instance mới được tạo let instance let counter class Counter constructor if instance throw new Error You can only create one instance instance this getInstance return this getCount return counter increment return counter decrement return counter const counter new Counter const counter new Counter Error You can only create one instance Perfect Bây giờtôi không thểtạo nhiều multiple cho instance hơn nữa Hãy export Counter từfile counter js Nhưng trước khi làm điều đó tôi nên đảm bảo rằng code không thểsửa đổi Singleton Không thểthêm hoặc sửa các property của một đối tượng điều này làm giảm rủi ro vôtình overwriting các value trên Singleton let instance let counter class Counter constructor if instance throw new Error You can only create one instance instance this getInstance return this getCount return counter increment return counter decrement return counter const singletonCounter Object freeze new Counter export default singletonCounter DONE Nhược điểmViệc khởi tạo trong một instance cóthểtiết kiệm rất nhiều memory Thay vìphải tạo memory cho từng instance mỗi lần new tôi chỉcần tạo memory cho instance đó vàmemory này được referenced cho toàn bộapp Tuy nhiên Singleton được coi làmột anti pattern nên thường không được sửdụng trong Javascript Trong nhiều programming languages nhưjava c c không thểtrực tiếp tạo các object theo cách tôi cóthểlàm trong javascript Trong OOP chúng ta cần tạo một class class này tạo ra object Object được tạo đócóvalue làinstance của class Tuy nhiên việc implementation một class ởcác vídụtrên thật sựCHỈĐỂHỌC CHO BIẾT THÔI CHỨMÉO GIÚP ÍCH ĐƯỢC Vìngày nay ởmột app ReactJS NextJS chúng ta thường sửdụng các global state thông qua các hệsinh thái nhưRedux hoặc Context thay vìsửdụng Singletons Mặc dùglobal state của chúng cóvẻtương tựnhưSingleton nhưng chúng chỉcho read only state thay vìthay đổi trực tiếp state của Singleton Khi sửdụng Redux Context chỉcófunction reducers cóthểupdate các state sau khi một component đãgửi một action thông qua dispatcher Tóm cái quần lại thay vìsửdụng Singleton đểquản lýmột app thìsuy nghĩnên dẹp đi vìgiờđây đãcóRedux Context	2022-07-31 02:08:41
海外TECH	DEV Community	Learn React Concept and Create your first app with React	https://dev.to/desmondowusudev/learn-react-concept-and-create-your-first-app-with-react-27g	Learn React Concept and Create your first app with ReactIn this article we will learn what and why React We will also create our first React application What is React React is a JavaScript library created by Facebook and released in the May of for front end development Front end development consists of HTML CSS and JavaScript As a front end developer you will easily find it is very difficult for the front end with HTML CSS and JavaScript when a website or web app is more interactive have a lot of different moving parts Eventually Facebook developers decided there must have a better way to manage these difficulties and that was when React was created as a JavaScript library to make front end development easier and faster Why React Interactive websites need to update the DOM Document Object Model whenever a change happens Compared to other libraries that manipulate the DOM React uses a Virtual DOM a lightweight copy of the actual DOM that allow updating the part of the website that has changed and this increases the speed of updates How to use ReactYou can use react in two ways Adding react to your website or Creating react app Adding React to a websiteReact can be added to a website without any special tools and installations But before that we have to include the React library as two script tags to the head of the HTML Document lt script src umd react development js gt crossorigin gt lt script gt lt script src umd react gt dom development js crossorigin gt lt script gt Next we need to add another script to enable the use of JSX JSX stands for JavaScript XML JSX allows us to write HTML in React JSX makes it easier to write and add HTML in React lt script src babel min js lt script gt Creating react appFacebook has created a tool called Create React App that makes it easy to set up a React project with a command Now we will be creating our first react app called my app To get started make sure you have a recent version of Node installed on your machine After the installation of the node Run the command below in your terminal with the path you want to create the app npx create react app my appAfter the execution of this command this will install all the required dependencies and a directory name my app will be created in the path you run the command Change the directory to the my app by running the command below in the terminal cd my appRun the app with this command npm startStart the app on localhost in any browser This is the default output of our project in the browser React Project StructureLet s explore the structure of our project by opening it using a code editor Now this is the project structure after creating react app By default it contains two directories public and src a ReadMe md file that contains how the app can be run and other information about the app It also contains a package json and package lock json file which contains the dependencies installed The public folder contains files related to how the application will display on the client the most important of those being index html which is the HTML template of our page The src folder contains all of the JavaScript CSS and image files that will be compiled into a bundle file and injected into index htmlAlthough there are other files in the src folder that comes with Create React App when it is generated the two files below are the only critical files index js This file is the entry point into our application In the index js file a method called ReactDOM render is used to find an element with id root in the HTML and add our React application inside of that element App js This file is the main component that will be rendered to the DOM which currently includes the React logo image and the default text that we see in the output How is React App compiled React uses a file loader In the case of Create React App Webpack is used to set up Webpack creates a bundle file containing the content of multiple files that need to be bundled together and it is all added together into a single file and injected into the index html file for compilation Note Webpack search for all CSS JavaScript and images in the src directory and create a bundle for them so they should always be in your src folder in case of Create React App Thank you for reading and let s connect Thank you for reading my blog Feel free to subscribe to my email newsletter and connect on LinkedInGitHub Twitter	2022-07-31 02:04:29
北海道	北海道新聞	エンゼルス大谷が２２号３ラン　レンジャーズ戦、三回に逆転	https://www.hokkaido-np.co.jp/article/712282/	大リーグ	2022-07-31 11:35:14
北海道	北海道新聞	キッザニア福岡がオープン　九州初、国内出店は１３年ぶり	https://www.hokkaido-np.co.jp/article/712279/	種類	2022-07-31 11:23:54
北海道	北海道新聞	三男も殺害疑いで再逮捕　次男窒息死の母親、神奈川県警	https://www.hokkaido-np.co.jp/article/712281/	神奈川県大和市	2022-07-31 11:30:49
北海道	北海道新聞	道内選出国会議員６人、旧統一教会と接点　選挙支援やイベント参加	https://www.hokkaido-np.co.jp/article/712208/	世界平和統一家庭連合	2022-07-31 11:12:28
北海道	北海道新聞	中国７月の景況感が節目割れ　ＰＭＩ、２カ月ぶり	https://www.hokkaido-np.co.jp/article/712278/	中国国家統計局	2022-07-31 11:01:00
ビジネス	東洋経済オンライン	ジンギスカン｢戦前は東京名物だった｣意外な事実 北海道より東京のほうが羊の消費量が多かった | 食品 | 東洋経済オンライン	https://toyokeizai.net/articles/-/606935?utm_source=rss&utm_medium=http&utm_campaign=link_back	東洋経済オンライン	2022-07-31 11:30:00
海外TECH	reddit	Ohtani hits a go-ahead 3-run home run to put the Angels ahead!	https://www.reddit.com/r/baseball/comments/wcdg6p/ohtani_hits_a_goahead_3run_home_run_to_put_the/	Ohtani hits a go ahead run home run to put the Angels ahead submitted by u Blazingbee to r baseball link comments	2022-07-31 02:02:47