| python |
Pythonタグが付けられた新着投稿 - Qiita |
Python: 剰余演算子を使わないでFizzBuzzしてみた |
https://qiita.com/ttatsf/items/2c500ff077118ff8698b
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fizzbuzz |
2023-02-11 03:02:45 |
| 海外TECH |
MakeUseOf |
How to Fix the Error Code 0x80072f8f - 0x20000 on Windows |
https://www.makeuseof.com/windows-error-code-0x80072f8f-0x20000-fix/
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installation |
2023-02-10 18:15:17 |
| 海外TECH |
MakeUseOf |
The Best Study Apps You Can Use in Any Browser |
https://www.makeuseof.com/study-apps-in-browser/
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study |
2023-02-10 18:15:16 |
| 海外TECH |
DEV Community |
When useEffect runs |
https://dev.to/cassidoo/when-useeffect-runs-3pf3
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When useEffect runsuseEffect is one of those React Preact hooks that most people have a love hate relationship with but like it or not it s good to understand how it works This is not the first blog post on the subject and it s certainly not going to be the last but hopefully I can explain some things to you about when and why it runs in your applications for you to use as a reference Please tell my friend what useEffect actually isYour friend asks a good question First of all let s talk about side effects in your applications When I say side effect I mean it is something that happens when other things are changing For example if I were to have a very simple add function function add x y return x y I could make a side effect of some other variable changing like so let z function add x y z z x this is the side effect it does not change the return value return x y Changing that z variable in here does not change the return value of the function it s just a side effect of adding x and y Now in React Preact it s a bit more complex and side effects aren t always a good thing And useEffect is usually for side effects Developer David Khourshid aptly said that useEffect should probably have been named useSynchronize because rather than it being an extra thing that should happen when state changes happen it should be more like things that happen to stay in sync with certain state changes When does useEffect get called So it does get a little hairy because useEffects behavior has changed a bit across framework updates but at a high level it s called on component mount and whenever anything in the dependency array changes I ll explain this more deeply So using this as our base useEffect gt your fetch call changes etc return gt clean up dependencyArray we re staying in sync with this The dependency arrayThat second parameter of useEffect is called the dependency array There s things that can happen here If the dependency array is empty useEffect is only called once note this has changed in React in development and strict mode because of Suspense things but this is how it is for Preact and pre React and I will talk about a workaround later in this post If it doesn t exist like it s omitted entirely then useEffect is called on every state changeIf it has a variable in it then useEffect is called when that variable changesIf that dependency array is populated you can think of the useEffect function as staying in sync with the variables in the array The return functionWhenever useEffect is about to be called again or whenever the component is about to be dismounted destroyed the clean up function is called Or to rephrase React Preact calls the clean up functions when a component unmounts or when an update is made and it needs to cancel the previous effect As another more filled out example useEffect gt let isCurrent true fetchUser uid then user gt if isCurrent setUser user return gt isCurrent false uid This might look a little confusing but the way it works is when the component is mounted the component will fetch the user If uid hasn t changed and the component stays mounted setUser will be called If uid changes in that time isCurrent will be set to false so setUser won t be called for that out of date HTTP call Stopping useEffect from being called on mountBesides controlling the dependency array variables the only other thing you might want to consider is saying hey I don t want this effect to be called on mount but ONLY on updates in the dependency array This is weird but it happens For this particular case you ll want to bring in the useRef hook I m not going to explain what that hook does here because that deserves its own blog post this one is pretty good from Robin Wieruch Let s assume you have some state variable called syncWithMe that you want to stay in sync with const hasMounted useRef false useEffect gt if hasMounted current code here only runs when syncWithMe changes else hasMounted current true syncWithMe This is called a ref flag In this example hasMounted acts as an instance variable that doesn t cause re renders or effect changes because it isn t a state variable So you set it to true when the component mounts and then whenever syncWithMe changes the effect function is called Having useEffect called only on mount in React Because of how the new Suspense functionality works and a bunch of other changes that happened in React useEffect needs to be manipulated more to run just once in development and strict mode it should be fine in production but eh this is still worth talking about It ll look a lot like our previous example but opposite const hasMounted useRef false useEffect gt if hasMounted current return do something hasMounted current true What if I don t want to use useEffect at all Then I think you should probably watch or read some thought leadery content around why it s bad Heh useEffect isn t bad it just has its own time and place and a lot of people have Opinionsabout how it should be used I do recommend watching this talk about useEffect in general It is titled Goodbye useEffect once again from David Khourshid who I referenced above and explains some nuances of when you should and shouldn t use it Hopefully this post was useful for you as a reference |
2023-02-10 18:39:22 |
| Apple |
AppleInsider - Frontpage News |
Here's what the Apple Glasgow retail store union negotiated for itself |
https://appleinsider.com/articles/23/02/10/heres-what-the-apple-glasgow-retail-store-union-negotiated-for-itself?utm_medium=rss
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Here x s what the Apple Glasgow retail store union negotiated for itselfApple has signed a union agreement for Apple Store staff in Glasgow and that union has shared the terms that it has negotiated Apple Glasgow shares union termsIn November Apple Glasgow finally unionized after several months of talks the first UK Apple Store to do so After that however workers had to sign up individually for the UK s GMB union before requesting Apple to recognize their union representation Read more |
2023-02-10 18:37:41 |
| Apple |
AppleInsider - Frontpage News |
Boulies Master Series chair review: Built for gaming, ideal for productivity |
https://appleinsider.com/articles/23/02/10/boulies-master-series-chair-review-built-for-gaming-ideal-for-productivity?utm_medium=rss
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Boulies Master Series chair review Built for gaming ideal for productivityYou shouldn t be spending too many hours sitting at a desk but since you probably need to at least you should have a good seat like the Boulies Master Series Chair Ultimately any chair has to do two things starting very first of all with how it has to be comfortable But chairs are not casual purchases so once you ve made the decision and bought one it also needs to last So really that s about lasting a long time in two senses ーthe hours today and hopefully the years to come The Boulies Master Series Chair is strong it s particularly good with at providing lower back support and it s quite quick to assemble too Read more |
2023-02-10 18:32:58 |
| 金融 |
RSS FILE - 日本証券業協会 |
『まなぶ わかる とうしチャンネル』がスタート！ |
https://www.jsda.or.jp/about/gyouji/qktoushi.html
|
Detail Nothing |
2023-02-10 18:20:00 |
| 金融 |
RSS FILE - 日本証券業協会 |
2月18日（土）サーバメンテナンスのお知らせ |
https://www.jsda.or.jp/shinchaku/servermaintenance/20230210113101.html
|
月日 |
2023-02-10 20:00:00 |
| ニュース |
BBC News - Home |
Great Yarmouth: Huge blast after unplanned WW2 bomb detonation |
https://www.bbc.co.uk/news/uk-england-norfolk-64604115?at_medium=RSS&at_campaign=KARANGA
|
detonationnorfolk |
2023-02-10 18:54:54 |
| ニュース |
BBC News - Home |
Epsom College deaths: No investigation into police contact with husband |
https://www.bbc.co.uk/news/uk-64603749?at_medium=RSS&at_campaign=KARANGA
|
firearms |
2023-02-10 18:35:05 |
| ニュース |
BBC News - Home |
Paris Olympics 2024: Russian participation 'can't be covered up by white flag' - Ukraine president |
https://www.bbc.co.uk/sport/olympics/64604212?at_medium=RSS&at_campaign=KARANGA
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Paris Olympics Russian participation x can x t be covered up by white flag x Ukraine presidentRussian participation in the Paris Olympics cannot be covered up with pretend neutrality or a white flag says Ukraine president Volodymr Zelensky |
2023-02-10 18:22:11 |
| ニュース |
BBC News - Home |
Turkey-Syria earthquake: Christian Atsu partner calls for equipment to aid rescue |
https://www.bbc.co.uk/sport/africa/64603833?at_medium=RSS&at_campaign=KARANGA
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Turkey Syria earthquake Christian Atsu partner calls for equipment to aid rescueChristian Atsu s partner calls for help to aid rescue and says confusing reports of his whereabouts have been shocking |
2023-02-10 18:07:03 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【クイズ】スーツのベルト通し「ありorなし」、どっちがよりフォーマル？ - 男のオフビジネス |
https://diamond.jp/articles/-/317527
|
冠婚葬祭 |
2023-02-11 04:00:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
実は「墓」だった世界の観光名所5選、タージ・マハルからカラフル墓地まで【写真付】 - 地球の歩き方ニュース＆レポート |
https://diamond.jp/articles/-/317387
|
地球の歩き方 |
2023-02-11 03:55:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
高齢女性の4人に3人がなる「アイフレイル」って？認知機能低下との関連も - ヘルスデーニュース |
https://diamond.jp/articles/-/317595
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介護予防 |
2023-02-11 03:50:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【お金を増やす】 個人投資家に欠かせない“シンプルにして王道”の成功法則 - 個人投資家もマネできる 世界の富裕層がお金を増やしている方法 |
https://diamond.jp/articles/-/315797
|
米国の富裕層の間では、米国以外の海外資産を組み入れるグローバル投資の動きが、以前にも増して加速しているという。 |
2023-02-11 03:45:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【国税OBが明かすお金】 億万長者だからこそ“ケチる”意外な出費とは？ - 元国税専門官がこっそり教える あなたの隣の億万長者 |
https://diamond.jp/articles/-/315882
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【国税OBが明かすお金】億万長者だからこそ“ケチる意外な出費とは元国税専門官がこっそり教えるあなたの隣の億万長者【大反響Amazonベストセラー第位】経済的に恵まれない母子家庭に育ち、高校・大学は奨学金を借りて卒業。 |
2023-02-11 03:40:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
「自炊」できる人になる、第一歩とは？ - てんきち母ちゃんの はじめての自炊 練習帖 |
https://diamond.jp/articles/-/317244
|
「自炊」できる人になる、第一歩とはてんきち母ちゃんのはじめての自炊練習帖お子さんの初めてのひとり暮らし、ご自身の転勤、単身赴任など‥‥。 |
2023-02-11 03:35:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
不登校、心の回復ロードマップ（休み始め～休養前期） - 不登校ー親子のための教科書 |
https://diamond.jp/articles/-/316880
|
|
2023-02-11 03:30:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【おせっかいが怖い？】職場の素敵な人は「気づかい」をするときに何を考えているのか？ - 気づかいの壁 |
https://diamond.jp/articles/-/316651
|
【おせっかいが怖い】職場の素敵な人は「気づかい」をするときに何を考えているのか気づかいの壁職場で困っている人を見かけても、「おせっかいだったらどうしよう…」と躊躇したり、「たぶん大丈夫だろう…」と自分に言い訳したりしていませんか「気がつくだけの人」で終わらず、「気がきく人」に変われる、とっておきのコツをご紹介する著書『気づかいの壁』。 |
2023-02-11 03:25:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【精神科医が教える】 どんな人も幸せになれる2つのステップ - 精神科医Tomyが教える 心の執着の手放し方 |
https://diamond.jp/articles/-/315784
|
【精神科医が教える】どんな人も幸せになれるつのステップ精神科医Tomyが教える心の執着の手放し方誰しも悩みや不安は尽きない。 |
2023-02-11 03:15:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【まんが】「もしかして毒親？」に育てられた人によくある特徴とは＜予約の取れないカウンセラーが教える＞ - あなたはもう、自分のために生きていい |
https://diamond.jp/articles/-/317429
|
twitter |
2023-02-11 03:10:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
【外資系社長が実践】効率的かつ漏れないタスク管理術 - １位思考 |
https://diamond.jp/articles/-/316972
|
|
2023-02-11 03:05:00 |
| ビジネス |
ダイヤモンド・オンライン - 新着記事 |
親欧米モルドバ政権の首相辞任 ウクライナ侵攻の余波 - WSJ発 |
https://diamond.jp/articles/-/317626
|
首相 |
2023-02-11 03:04:00 |
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