投稿時間:2023-01-23 05:20:38 RSSフィード2023-01-23 05:00 分まとめ(24件)

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海外TECH	MakeUseOf	How to Fix Valorant's Download Speed Stuck at 0.1KB/s on Windows	https://www.makeuseof.com/windows-valorant-slow-download-fix/	windows	2023-01-22 19:15:15
海外TECH	MakeUseOf	15 HTML5 Browser Games That Don't Need Adobe Flash	https://www.makeuseof.com/tag/html5-browser-games-flash/	flash	2023-01-22 19:01:15
海外TECH	MakeUseOf	How to Use ESLint With the Airbnb JavaScript Style Guide	https://www.makeuseof.com/eslint-with-airbnb-javascript-style-guide/	airbnb	2023-01-22 19:01:15
海外TECH	DEV Community	Introduction To 11 Core JavaScript Functions To Improve Code Quality	https://dev.to/paulknulst/introduction-to-11-core-javascript-functions-to-improve-code-quality-5hce	Introduction To Core JavaScript Functions To Improve Code QualityJavaScript Is Everywhere Even In Spaceships Level Up Your Skills amp Learn Core JavaScript Functions To Remarkably Improve Code Quality Paul Knulst  in Programming •Jun • min readIt doesn t care if you working with backend or frontend or even SPACESHIPS JavaScript could be used everywhere because it is a quite flexible language It has hardcore functional programming patterns as well as classes and its similarity to other C like languages enables an easy transition for every developer If you want to level up your skills in JavaScript I would suggest learning about practicing and mastering the following very important core functions that are available in the language You will not need every function for solving most problems but they can help you to avoid heavy lifting in some cases while in others they will reduce the amount of code that you have to write map One of the most important JavaScript functions is map Also it is one function that gives the most trouble to people who learn JavaScript This happens because the way this function works is an idea taken from Functional Programming which most developers are not familiar with It seems strange or even wrong to our biased brains The function map is very simple It attaches itself to an array and converts each item into something else resulting in a new array This conversion is done by an anonymous function provided in the map brackets That s all that map does At first the syntax for map might take some time to get used to but after mastering it will be one of your best friends working with JavaScript Why You Might Want To Use map For instance let s say we recorded the amount of water in a fountain for each day of the last week and stored it in an array At the end of the week you are told that the measurement tool was not as accurate as possible and the amount of water was liters less than it should be With the map function you can easily solve this issue by doing this const dailyReadings const correctedDailyReadings dailyReadings map day gt day console log correctedDailyReadings gives You can find another very practical example in the world of React when you create DOM element lists from arrays This is a common pattern in React and will be achieved by this piece of code export default articles gt return links map article gt return lt div className link key article id gt lt div className article name gt article name lt div gt lt div className article desc gt article description lt div gt lt div gt Now you can argue that map is nothing but another implementation of a for loop and you will be right but notice that maybe this is your object oriented trained mind that makes this argument filter filter is an unbelievable useful JavaScript function that you can use in many situations because it filters an array based on a given rule logic This rule logic will be provided as anonymous functions To show how filter is working we can reuse the previous fountain example Assume that the array contains the amount of water stored within the fountain This time measurement tool works as expected Now we want to find out how often the amount was lower than liters This can be achieved using the filter function const dailyReadings const daysWithLowAmount dailyReadings filter day gt return day lt console log Days with low amount of water daysWithLowAmount length console log daysWithLowAmount It is important that the anonymous function that you pass to filter has to return a Boolean value true or false The Boolean expression is used by the filter function to determine if a value should be inserted in the newly generated array or not Within the anonymous function you can implement any amount of complex logic to filter the data you can read user inputs make any API call and so on as long as you return a Boolean value in the end BEWARE Keep in mind that filter always returns an array This is also the case if the filtered data is empty Often this leads to subtle bugs within code snippets because filter is used this way const dailyReadings const daysWithCriticalAmount dailyReadings filter day gt return day lt if daysWithCriticalAmount console log The amount of water was critical else console log The amount of water was normal Did you notice something The if condition in the end checks daysWithCriticalAmount which is actually an array that is empty because there was no day with less water than Surprisingly this mistake is done too often if you are rushing toward a deadline and just want to implement a filter method fast The problem with this piece of code is that especially JavaScript Yeah JavaScript is weird is an inconsistent language in many ways Sometimes the truthiness of things is one of them As you maybe know in JavaScript true returns false and you may think that the above code is correct Unfortunately within an if condition evaluates to true In other words the else block will never be executed Fixing this problem is very easy because you only have to check if the length of the resulting array is greater or equal to reduce Compared to all the other functions in this article reduce is competing for the first place of confusing weird and complex JavaScript functions Although this function is highly important and results in elegant code in many situations it is avoided by many JavaScript developers They prefer to write code without the help of reduce One reason for this is the complexity of reduce It is very hard to understand the concept and the execution of this function Furthermore if you read its description you have to re read it several times and still you doubt yourself if you read it wrong Happens to me until I saw it in action The reduce function is used to reduce obvious isn t it the given array to a single value This could be a number a string a function an object or whatever else If you want to use the reduce function to reduce an array you need to supply the needed logic by providing a function In general this function will be called the reducer function that transforms the first argument to reduce Also it contains a second argument that is a starting value and can be a number a string etc The function itself will look like this array reduce reducerFunction startValue startValue The startValue passed to reduce function is the starting value obvious for the calculation you want to process with the reducerFunction For example if you want to execute an addition you might start with and if you want to do a multiplication you should use a value of reducerFunction As mentioned before the reducer function is used to convert the array into a single value It has two arguments  an accumulator and a variable to store the current value The accumulator is just a fancy name describing the variable that contains the result of the calculation it is like using total to sum up all items in an array Within the reducer function the accumulator will be initially set to the starting value and then the calculation will be performed step by step iterating through the array while the result of each step is saved within the accumulator The second argument of the reducer function is currentValue and will contain the value within the array at a given position in a specific step For example in step while executing the reducer function the variable currentValue will contain the second value from the input array With all this information we should look at the following example which will add every value from an input array within the reducer function const input const result input reduce acc currentValue gt acc currentValue console log result Within the first line we define the input array that s holding all the numbers we want to add The next line will contain the input reduce call which defines the starting value for acc to be because in an addition we should start with to not influence the result The reducer functions body acc currentValue gt acc currentValue does a simple addition of the current value and the value that is stored in the accumulator If you would do this addition with a for loop it would look like this const input let result for let i i lt input length i result input i console log total As you can see the simple for loop example is much longer and not as elegant as using reduce some Imagine you have an array of objects containing Students and their scores in an exam Now you want to know if there are students in your class that have a score that is greater than and it does not care if there is one or multiple students that passed that exam with more than If you want to do this in JavaScript you can solve the problem while using a loop and a variable that is set to true after the first person is found that has a score greater const students name Stud score name Stud score name Stud score let over false for let i i lt students length i if students i score gt over true break if over console log There are students with exceptional score else console log Unfortunately nothing is exceptional For me this code looks very ugly verbose or horrible It could be optimized by using the map function that was described earlier but the solution will still be a little bit clunky Luckily JavaScript has a rather neat function called some that is available in the core language works with arrays and returns a Boolean value While providing an anonymous function it will filter the input array to solve the problem elegantly const students name Stud score name Stud score name Stud score if students some student gt return student score gt console log There are students with exceptional score else console log Unfortunately nothing is exceptional You can see it gets the same input and will produce the same result but in a more elegant way Also the amount of code is reduced and it is much more readable than before every Another function that already exists in the JavaScript core language is every This function will return a Boolean value like some but will test all items within the input array To do this you have to provide again an anonymous function As an example we will test if every student has passed the exam by achieving an exam score of or more const students name Stud score name Stud score name Stud score if students every student gt return student score gt console log All students passed the exam else console log Unfortunately not all students did well Like some this function creates elegant readable and maintainable code that is short includes Often if I want to check an array of the existence of substrings I will use indexOf Unfortunately I have to look up the docs to know how their return values are Luckily there is a nice alternative in JavaScript that can be used to achieve this includes The usage is very easy and it is case sensitive I guess you wished for it anyway See the following code snippet for an example const numbers console log numbers includes trueconst name Paul Knulst console log name includes paul false because first letter is in smallconsole log name includes Paul true as expectedHowever includes can only compare simple values and no objects const user a b c console log user includes b does not work because objects does not have an includes method shift If you want to remove the first element of an array shift is the method you should use because it is easy to remember and intuitive Notice that you also can do it with splice see it later but shift is easier const input const first input shift console log input gives Array console log first gives As you can see here shift alters the array it is called on and returns the removed element Notice shift is extremely inefficient and should be avoided if you are working with large arrays Too many calls of shift on large arrays can break your applications unshift In contrast to shift which removes one element this function is used to add a new element at the beginning of the array const input input unshift console log input expected output Array Notice Like shift unshift is extremely inefficient and should be avoided if you are working with large arrays Too many calls of unshift on large arrays can break your applications slice In JavaScript exist a concept that is called slicing which is a function to create a new string containing a part of an original string by providing a starting index and an end index Now with help of the indexOf function you can slice an input string to retrieve the searched substring const input This is a cool article about mandatory JavaScript functions that every developer shoud know const start input indexOf cool const end input indexOf that const headline input slice start end console log headline cool article about mandatory JavaScript functions Notice that the start index is included in the resulting array but the end index is not Also you can see that the space between functions and that is also not sliced Additionally slicing can also be used with arrays const animals ant bison camel duck elephant console log animals slice camel duck elephant console log animals slice Array camel duck splice splice sounds like slice and could be compared with it because both functions create new arrays or strings from the original ones The main small but very important difference is that splice removes changes or adds elements but modifies the original array This destructuring of the original array can lead to huge problems if you do not fully understand how deep copies and references work in JavaScript The following example will show how splice can be used const months Jan March April June const feb months splice Feb inserts at index console log months Jan Feb March April June console log feb const may months splice May replaces element at index console log months Jan Feb March April May console log may June You can see here that splice manipulates the original array If you remove an item it will also return the removed entry but if you add an entry the return array will be empty fill The last JavaScript function is fill and is used to change several items to a single value or even reset the full array to their initial values If you need this fill can help you avoid loops to reset the values of an array Furthermore the function can be used to replace some or all entries from the array with a given value You can see how it works within the following example const input console log input fill console log input fill console log input fill ConclusionThis list contains functions that most JavaScript developers encounter and use in their careers Although it is long it is by no means complete because there are so many more minor but very useful functions in JavaScript reverse sort find flat entries I would suggest that you read about these functions because you will at any point use them in your JavaScript project Furthermore whenever you can you should explore the core language or famous utility libraries such as lodash to deepen your JavaScript knowledge It will result in massive productivity and you will learn to create cleaner compact readable maintainable and usable code This article was originally published on my blog at Feel free to connect with me on my blog Medium LinkedIn Twitter and GitHub Support this contentIf you like this content please consider supporting me You can share it on social media or buy me a coffee Any support helps Furthermore you can sign up for my newsletter to show your contribution to my content See the contribute page for all free or paid ways to say thank you Thanks Photo by Kyle Glenn Unsplash	2023-01-22 19:09:39
医療系	医療介護 CBnews	救急医療管理加算の今、そしてこれからを考える-先が見えない時代の戦略的病院経営（188）	https://www.cbnews.jp/news/entry/20230120124557	救急医療	2023-01-23 05:00:00
ニュース	@日本経済新聞 電子版	「債券ルネサンス」が始まる　インフレ鈍化でマネー回帰 https://t.co/dlviVKhNYh	https://twitter.com/nikkei/statuses/1617245872768815104	鈍化	2023-01-22 19:40:37
ニュース	@日本経済新聞 電子版	社員の声、聞こえてますか　物言えぬ組織は成長止める https://t.co/wbP4BhROJz	https://twitter.com/nikkei/statuses/1617238094343995393	組織	2023-01-22 19:09:43
ニュース	BBC News - Home	National Grid puts coal plants on standby to supply electricity	https://www.bbc.co.uk/news/business-64367504?at_medium=RSS&at_campaign=KARANGA	orders	2023-01-22 19:21:29
ニュース	BBC News - Home	Arsenal 3-2 Manchester United: Mikel Arteta says his side showed 'emotional control' in 'beautiful' victory	https://www.bbc.co.uk/sport/av/football/64297451?at_medium=RSS&at_campaign=KARANGA	Arsenal Manchester United Mikel Arteta says his side showed x emotional control x in x beautiful x victoryArsenal manager Mikel Arteta says his side showed emotional control in their beautiful victory over Manchester United in the Premier League	2023-01-22 19:19:28
ニュース	BBC News - Home	European Champions Cup: Edinburgh 20-14 Saracens	https://www.bbc.co.uk/sport/rugby-union/64368288?at_medium=RSS&at_campaign=KARANGA	European Champions Cup Edinburgh SaracensA late try by Ben Earl secures a top four place and a home tie for Saracens against Ospreys in the last of the Champions Cup despite suffering defeat in Edinburgh	2023-01-22 19:29:25
ビジネス	ダイヤモンド・オンライン - 新着記事	東北のレジェンド農家直伝、農産物の利益率を高める「食卓イノベーション」の起こし方【動画】 - カリスマ農家の「儲かる農業」	https://diamond.jp/articles/-/316063	東北のレジェンド農家直伝、農産物の利益率を高める「食卓イノベーション」の起こし方【動画】カリスマ農家の「儲かる農業」東北のレジェンド農家が明かす、農産物の利益率を高める秘訣とは特集『カリスマ農家の儲かる農業』舞台ファーム編の第回は、サプライチェーン全体で新たな価値を創造する「食卓イノベーション」の考え方を徹底解説。	2023-01-23 04:50:00
ビジネス	ダイヤモンド・オンライン - 新着記事	セブン＆アイ、そごう・西武売却で大紛糾！強引な交渉が招いた「池袋動乱」の衝撃 - セブン解体 池袋動乱編	https://diamond.jp/articles/-/316354	セブンアイ、そごう・西武売却で大紛糾強引な交渉が招いた「池袋動乱」の衝撃セブン解体池袋動乱編セブンアイ・ホールディングス“解体の象徴といえる百貨店子会社そごう・西武の売却交渉が、「動乱」の様相を呈している。	2023-01-23 04:45:00
ビジネス	ダイヤモンド・オンライン - 新着記事	相続・生前贈与が65年ぶり大改正！新ルールに完全対応「駆け込み節税」対策術 - 相続＆生前贈与 65年ぶり大改正	https://diamond.jp/articles/-/316364	相続・生前贈与が年ぶり大改正新ルールに完全対応「駆け込み節税」対策術相続生前贈与年ぶり大改正生前贈与と相続のルールが年ぶりに大改正される。	2023-01-23 04:40:00
ビジネス	ダイヤモンド・オンライン - 新着記事	新人・新戦力が育たないのは「1人目の上司」の能力が低いから - 「40代で戦力外」にならない！新・仕事の鉄則	https://diamond.jp/articles/-/316314	鉄則	2023-01-23 04:35:00
ビジネス	ダイヤモンド・オンライン - 新着記事	2023年の日本株「上昇継続」が期待できる理由、世界景気の減速をカバーする中長期循環 - 政策・マーケットラボ	https://diamond.jp/articles/-/316400	年の日本株「上昇継続」が期待できる理由、世界景気の減速をカバーする中長期循環政策・マーケットラボ米国、欧州などでの利上げ、金融引き締めが続く中で、世界経済は減速しており、日本景気は、製造業を中心に弱含みの動きを示している。	2023-01-23 04:30:00
ビジネス	ダイヤモンド・オンライン - 新着記事	年収が高い会社ランキング2022最新版【九州＆沖縄地方トップ5】5位安川電機、1位は？ - ニッポンなんでもランキング！	https://diamond.jp/articles/-/316412	上場企業	2023-01-23 04:25:00
ビジネス	ダイヤモンド・オンライン - 新着記事	年収が高い会社ランキング2022最新版【九州＆沖縄地方・100社完全版】TOTOやJR九州は何位？ - ニッポンなんでもランキング！	https://diamond.jp/articles/-/316411		2023-01-23 04:25:00
ビジネス	ダイヤモンド・オンライン - 新着記事	さわかみ投信の創業者・澤上篤人氏が「金融緩和バブルの崩壊は時間の問題」と断言する根拠 - 今週の週刊ダイヤモンド　ここが見どころ	https://diamond.jp/articles/-/316424	さわかみ投信の創業者・澤上篤人氏が「金融緩和バブルの崩壊は時間の問題」と断言する根拠今週の週刊ダイヤモンドここが見どころ週刊ダイヤモンド月日号の第一特集は『「お金」入門』です。	2023-01-23 04:20:00
ビジネス	ダイヤモンド・オンライン - 新着記事	「円高の逆襲」継続へ、背景に米国のインフレ鎮静化と日本の出遅れインフレ - 政策・マーケットラボ	https://diamond.jp/articles/-/316460	外為市場	2023-01-23 04:15:00
ビジネス	ダイヤモンド・オンライン - 新着記事	JR常磐線・千代田線に賠償求め「2万6980円訴訟」、利用者が訴える理不尽 - News&Analysis	https://diamond.jp/articles/-/316417	newsampampanalysisjr	2023-01-23 04:10:00
ビジネス	ダイヤモンド・オンライン - 新着記事	成功する人に共通する「5つの原則」、あなたも練習で習得できる - 要約の達人　from flier	https://diamond.jp/articles/-/316440	成功する人に共通する「つの原則」、あなたも練習で習得できる要約の達人fromflier仕事で成功を収める人とそうでない人の違いは何だろうか。	2023-01-23 04:05:00
ビジネス	ダイヤモンド・オンライン - 新着記事	金融業界の熾烈な採用競争、大和証券「エキスパート・コース」新設の意気込み - 親と子の「就活最前線」	https://diamond.jp/articles/-/316418	大和証券	2023-01-23 04:03:00
ビジネス	東洋経済オンライン	NHKが絶対に死守したい｢受信料ビジネス｣の全貌 ｢強制サブスク｣と化す公共放送のまやかし | 最新の週刊東洋経済 | 東洋経済オンライン	https://toyokeizai.net/articles/-/647125?utm_source=rss&utm_medium=http&utm_campaign=link_back	公共放送	2023-01-23 04:50:00
ビジネス	東洋経済オンライン	元徴用工問題のボールは韓国から日本に移った 外交が韓国司法から主導権を奪い返せるか | 外交・国際政治 | 東洋経済オンライン	https://toyokeizai.net/articles/-/647464?utm_source=rss&utm_medium=http&utm_campaign=link_back	韓国政府	2023-01-23 04:30:00