投稿時間:2021-11-28 06:24:13 RSSフィード2021-11-28 06:00 分まとめ(28件)

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TECH	Engadget Japanese	2014年11月28日、ウォッチバンドヒンジを採用した「YOGA 3 Pro」が発売されました：今日は何の日？	https://japanese.engadget.com/today-203019513.html	yogapro	2021-11-27 20:30:19
海外TECH	MakeUseOf	Blurry Content on a 4K Monitor? 5 Quick Fixes	https://www.makeuseof.com/blurry-content-4k-monitor-quick-fixes/	fixes	2021-11-27 20:45:33
海外TECH	MakeUseOf	The 5 Best Color Picker Apps for Mac	https://www.makeuseof.com/tag/color-picker-apps-mac/	colors	2021-11-27 20:30:12
海外TECH	MakeUseOf	4 Digital Payment Methods That Will Replace Debit and Credit Cards	https://www.makeuseof.com/digital-payment-methods-replace-cards/	digital	2021-11-27 20:30:12
海外TECH	MakeUseOf	How to Install and Use Neofetch on Windows	https://www.makeuseof.com/how-to-install-and-use-neofetch-on-windows/	windows	2021-11-27 20:15:11
海外TECH	DEV Community	Interesting C++ bug involving `std::cin` for input.	https://dev.to/baenencalin/interesting-c-bug-involving-stdcin-for-input-14gg	Interesting C bug involving std cin for input So I was making hangman for fun and I hadunsigned short guesses std string word std cin lt lt guesses And I discovered something interesting I was just playing around and I typed and spammed a bunch of s Sort of like the following And then it did something really strange it skipped the next std cin command which was the one for word And then it kept repeating printing things over and over probably because I was in a while true but it didn t bother to stop when it hit std cin even on the next loop iteration instead constantly having the number be equal to or in other words the bit integer unsigned short limit Even if I enter the unsigned short limit plus one it still bugs out in this crazy way Here s an image of what happens after I do this This is what should happen normally Strangely this bug will also happen if I pass any strings that include a space character in them for answer for some reason This is my code int main while true unsigned short guesses std string answer std cout lt lt Enter the amount of guesses to allow std cin gt gt guesses std cout lt lt Enter the word for P to guess std cin gt gt answer std cout lt lt Guesses lt lt guesses lt lt lt lt Word lt lt answer lt lt n If anyone knows what s causing these bugs and how I can fix them let me know Thanks Cheers	2021-11-27 20:38:29
海外TECH	DEV Community	A Story Of React States.	https://dev.to/alimobasheri/a-story-of-react-states-5di4	A Story Of React States It s hard to maintain a state Harder to maintain a UI And near impossible to keep a user happy No matter how well you plan disintegration always happens React is a well known web UI library with a long history of state implementation Components shape the application But it s a state s job to keep it inside the sanity borders That is unless it drives the developer insane before achieving this goal Different seasons different states We know how the seasons pass In spring flowers bloom In summer sweats run down the armpits With autumn leaves leave the branches And who will forget the snowy days of winter Hint People who live after global warming makes its debut Nature can resemble a big React Component A part of life on Earth But it goes through various phases We know each as a season Different parts of a front end application can be in different phases too They are the results of changes in what we call a state An introduction to our study Imagine a man with a bad temper He swears in hot summers And beats people when it gets cold enough No one can predict him You might say that he is affected by the weather For example he is a kind man during springs and even sings poems when it rains Winters are cold and make him impatient That is why he will prefer to get his deals done by action rather than talks Such a man lacks good state management making him unable to control his behavior A similar issue can exist in a front end application too That s when it gives inappropriate responses or gives none at all Then let s have a quick review of what a state is in a React Component React Components State From the React documentation State is similar to props but it is private and fully controlled by the component Props themselves are Objects Their keys are the name of the attributes we pass to the component through JSX And their values are that of the corresponding attributes While a state can be an attribute or a collection of them it can be an Object a String or any other JavaScript Type But what is the main difference between a state and a prop Answer The component receives props from its parent while it creates and controls its own state What is the actual problem At this point we can ask a question What makes a great application Perhaps dedication to its end The desire to deliver satisfaction A sense of being useful What we may call confidence A bad application isn t pushed by these things It already feels satisfied and confident It is directed by more solid things It is affected by data flows By a powerful inertia It s uncareful about user expectations And it s rarely suited for different user stories It only works if everything is ok Which is seldom the case in a real world application Can we make a state using a simple variable Let s say that we ve a component called Nature This component has a main state variable season First let s declare it just using a simple JavaScript variable function Nature props let season spring return lt p gt Currently it is season lt p gt The line const season spring is where we declared our state variable The output HTML looks like this lt p gt Currently it is spring lt p gt Let s add a button to our function s return We pass its onClick event a callback which will try to change the variable season s value to summer function Nature props let season spring const changeSeason gt season summer return lt div gt lt p gt Currently it is season lt p gt lt button onClick changeSeason gt Click to change season lt button gt lt div gt It will output the previous result with an added button Yet if you click on the button it won t change the season s name in the output The variable s value changes to summer but the onClick will never result in a change in the output Why To answer that we should learn about React Hooks Flow This is where things get interesting Stories of a component s madness Events A sequence of them shapes what we may know as a storyline For example you may have just graduated from high school This is an important event for you that also describes your level of education Our memories and personalities are made of events Our resumes are fully contented by them And to get our life move on we expect future events too A Component s lifecycle is full of events We re going to have a look at an example Assume a submit button which is used to register user information The button is disabled until the user fills the required fields correctly The form component uses a state variable to enable the button It works just fine The user fills in the form The gray button turns blue and the user clicks on it In the background the API request for registering is sent But the user is not informed They don t see any loading element or message They think it hasn t worked and they click on it again And guess what Another request is sent in the background The first request is successful to register the user The component is designed to redirect the user after success But The response to the second request comes in a hurry Acknowledging the component that the user s email is a duplicate Now another state variable holding the email duplication error turns true The component gives the user an error informing that the email is a duplication and the redirect just doesn t work because the error state is not false The component has been instructed not to redirect if the error state is not clear Which is irrelevant And is a bad state management We re faced with several events in this example One of them happens when the form is filled Another occurs when the user clicks on the button The last event is when the response has arrived We as users and developers can understand these events But a UI library such as React is not as smart as a human It has to be instructed what the events are and it has to register them beforehand That s what we call Components Hook Flow React Components Hook FlowHooks were added to React from version They were a major update at the time as they empowered the stateless function components with abilities that were only available in Class Components It was a good thing to have the ability to run effects and change states in a functional component But a Class Component also provided the developers with Lifecycle Methods eg componentDidMount or shouldComponentUpdate The functional components and hooks don t provide us with Lifecycle Methods Instead different hooks in a functional component are run in a specific order so that the developer can implement the same Lifecycle Logics by considering this order The Hooks Flow is made of main stages Mount Update and Unmount When a component mounts for the first time its initial values are set These include the useState and useReducer initializer functions Then it will continue the rest of the codes you have added in your functional component up until it reaches the returned value Then before rendering the returned JSX it will run your layoutEffects which you create using the useLayoutEffect hook Then the browser paints the screen to reflect the React Virtual DOM Then the effects which you have registered using useEffect are called It s a straightforward flow for mounting the component But then the component will need to update This can happen due to two reasons either there s a change in props or a state has been updated The updating stage has its own steps It will run your functional component and update the DOM based on the new changes resulting from the updated state In the next step it s going to clear the previous layoutEffects afterward it will run the layoutEffects The browser repaints the screen to reflect the changes And finally before running the effects react is going to clean the previous effects The updating stage has a similar order of steps to the mounting one It only differs in the details Like the mounting stage uses initial state values and the updating stage uses the new ones The mounting stage runs the effects but the updating one first will try to clear the effects caused by previous updating or mounting stages of the component The third stage in this flow as we mentioned is the unmounting stage In this stage the whole component will be cleared from the screen So nothing is going to happen except that React will try to clear any remaining layoutEffects and effects Now that we know the React Hooks Flow we can realize why storing our Component s state inside a simple variable won t cause a change in the DOM Because React won t update the DOM unless it is sure that something has changed The way React listens to the state changes is like how we can add eventListeners in JS For example assume a text input element We can add listeners for its value change or when the input is blurred React adds listeners to the state variables changes And when we call the stateSetter functions this event is fired and then React knows how to update the DOM Then let s rewrite our previous code to make it work The right way to declare a stateReact provides us with the useState hook to bring states to functional components To initialize a state you need to call the hook and pass it the state s initial value The hook will return an array of two elements The first element in the array is the state s value and the second element is the state setter function We ll use this function to add the season state to our component We ll also rewrite our changeSeason function to use the state setter function returned by useState function Nature props let season setSeason useState spring const changeSeason gt setSeason summer return lt div gt lt p gt Currently it is season lt p gt lt button onClick changeSeason gt Click to change season lt button gt lt div gt Now after rendering this component if we try to click on the button we ll see the season name in the paragraph changes to summer In the above code the variable season refers to the first element returned by useState which holds the latest state value And setSeason is the method we can use to update the state s value We learned how we can bring states to a functional component in React And we ve also learned how states work in a more fundamental way Knowing the right way to declare a state a great question pops up Is there also a right way to use states in React Life is a journey So is React development No one is like anyone else No one shares the exact same interests as anyone else We re all unique through our preferences And this uniqueness also affects the way we live our lives Different React projects also have their own differences They differ in how they manage their states their effects their components trees or even their folder structures No one state that you should structure a React project in a specific way You have to understand the underlying mindset which React uses for managing its re renders props states effects and etc Throughout this article we learned about the mindset behind how React implements states I hope it can help you to better understand what they are and why they matter This is already a long article and I ll end it here as I don t want to bore you with extra information But let me add one more tip Anytime you were in doubt whether you should use a state or not try to answer this question Should changes in this variable cause a re render Credits for cover image M Schuppich Shutterstock I have no content creation experience in English Twitter yet But I d like to start tweeting about different subjects of programming in my Twitter account I d really be thankful of your support if you start following my twitter account	2021-11-27 20:13:09
海外TECH	DEV Community	The first code in JavaScript	https://dev.to/ilosrim/the-first-code-in-javascript-24f0	The first code in JavaScriptlet hi Hello World console log hi	2021-11-27 20:04:55
海外TECH	WIRED	The Best Black Friday Vacuuming and Cleaning Deals	https://www.wired.com/story/best-black-friday-vacuum-deals-2021-1	roborock	2021-11-27 20:23:00
海外TECH	WIRED	The Best Black Friday Deals on Fitness and Outdoor Gear	https://www.wired.com/story/best-black-friday-fitness-deals-outdoors-2021-1	trackers	2021-11-27 20:08:00
ニュース	BBC News - Home	Storm Arwen: Third person dies as gale-force winds hit UK	https://www.bbc.co.uk/news/uk-59435965?at_medium=RSS&at_campaign=KARANGA	arwen	2021-11-27 20:38:46
ニュース	BBC News - Home	Covid: Dozens test positive on SA-Netherlands flights	https://www.bbc.co.uk/news/world-europe-59442149?at_medium=RSS&at_campaign=KARANGA	omicron	2021-11-27 20:41:41
ニュース	BBC News - Home	'He is the perfect signing' - is Jota key to Liverpool's success?	https://www.bbc.co.uk/sport/football/59446914?at_medium=RSS&at_campaign=KARANGA	x He is the perfect signing x is Jota key to Liverpool x s success Liverpool have scored more goals after games than in any other top flight season so is perfect signing Diogo Jota key to their success	2021-11-27 20:21:16
ビジネス	ダイヤモンド・オンライン - 新着記事	楽天の携帯巨額赤字で急浮上「3つの資金繰り策」、生煮えの楽天銀行IPO案にすがる窮地 - 決算書100本ノック！ 2021冬	https://diamond.jp/articles/-/288022	日本郵政	2021-11-28 05:25:00
ビジネス	ダイヤモンド・オンライン - 新着記事	スルガ銀行に迫るアパマン融資“帳消しリスク”の「意外な試算結果」と、2つ目の火種の正体 - 決算書100本ノック！ 2021冬	https://diamond.jp/articles/-/288021	スルガ銀行に迫るアパマン融資“帳消しリスクの「意外な試算結果」と、つ目の火種の正体決算書本ノック冬年に勃発したシェアハウス融資問題がようやく解決に向かおうとしているスルガ銀行。	2021-11-28 05:15:00
ビジネス	ダイヤモンド・オンライン - 新着記事	社長が「絶対に入社してほしい」と思うハイクラス人材の条件【キャリア・見逃し配信】 - 見逃し配信	https://diamond.jp/articles/-/288859	配信	2021-11-28 05:12:00
ビジネス	ダイヤモンド・オンライン - 新着記事	コロワイド、ワタミ、大庄…コロナ前比で減収率が「最も深刻」だったのは？ - ダイヤモンド 決算報	https://diamond.jp/articles/-/288807		2021-11-28 05:10:00
ビジネス	ダイヤモンド・オンライン - 新着記事	アインシュタインの「天才脳」を研究して判明、常人との3つの違いとは？ - 「天才脳と子育て」の真実	https://diamond.jp/articles/-/288769	物理学者	2021-11-28 05:09:00
ビジネス	ダイヤモンド・オンライン - 新着記事	小学校お受験に強いのは？「子どもの向き不向き」がわかる3タイプ診断テスト - 「天才脳と子育て」の真実	https://diamond.jp/articles/-/288772	早期教育	2021-11-28 05:07:00
ビジネス	ダイヤモンド・オンライン - 新着記事	コロナでクラスターの「シェアハウス」、それでも若者人気が底堅い理由 - ニュース3面鏡	https://diamond.jp/articles/-/285971		2021-11-28 05:05:00
北海道	北海道新聞	１５歳ワリエワ、ＧＰ２連勝　フリー、合計とも世界最高	https://www.hokkaido-np.co.jp/article/616400/	世界最高	2021-11-28 05:12:00
北海道	北海道新聞	小林陵侑、逆転で今季初Ｖ　スキー男子で単独最多２０勝	https://www.hokkaido-np.co.jp/article/616399/	小林陵侑	2021-11-28 05:12:00
北海道	北海道新聞	男子５００ｍで菊池耕太８位　ショートトラックＷ杯第４戦	https://www.hokkaido-np.co.jp/article/616401/	北京冬季五輪	2021-11-28 05:12:00
北海道	北海道新聞	独、伊でオミクロン株確認　アフリカ南部から渡航	https://www.hokkaido-np.co.jp/article/616396/	確認	2021-11-28 05:12:00
北海道	北海道新聞	英、コロナ規制を再導入　新変異株の確認で	https://www.hokkaido-np.co.jp/article/616397/	新型コロナウイルス	2021-11-28 05:12:00
北海道	北海道新聞	張本、早田組がメダル確定　卓球の世界選手権第５日	https://www.hokkaido-np.co.jp/article/616398/	世界選手権	2021-11-28 05:12:00
ビジネス	東洋経済オンライン	新生銀､株主総会ドタキャンが残した後味の悪さ 少数株主の利益がないがしろにされていないか | 金融業界 | 東洋経済オンライン	https://toyokeizai.net/articles/-/471913?utm_source=rss&utm_medium=http&utm_campaign=link_back	臨時株主総会	2021-11-28 05:30:00
海外TECH	reddit	[Postgame Thread] Michigan Defeats Ohio State 42-27	https://www.reddit.com/r/CFB/comments/r3mcy9/postgame_thread_michigan_defeats_ohio_state_4227/	Postgame Thread Michigan Defeats Ohio State Box Score provided by ESPN Team T Ohio State Michigan Made with the r CFB Game Thread Generator submitted by u CFB Referee to r CFB link comments	2021-11-27 20:38:04