投稿時間:2022-09-23 20:32:18 RSSフィード2022-09-23 20:00 分まとめ(36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	気になる、記になる…	ソニーの安価で高評価なワイヤレスヘッドホン｢WH-CH510｣の後継モデル｢WH-CH520｣がFCCを通過	https://taisy0.com/2022/09/23/162571.html	mysmartprice	2022-09-23 10:41:18
AWS	AWS Compute Blog	Integrating Amazon MemoryDB for Redis with Java-based AWS Lambda	https://aws.amazon.com/blogs/compute/integrating-amazon-memorydb-for-redis-with-java-based-aws-lambda/	Integrating Amazon MemoryDB for Redis with Java based AWS LambdaThis post is written by Mansi Y Doshi Consultant and Aditya Goteti Sr Lead Consultant Enterprises are modernizing and migrating their applications to the AWS Cloud to improve scalability reduce cost innovate and reduce time to market new features Legacy applications are often built with RDBMS as the only backend solution Modernizing legacy Java applications …	2022-09-23 10:55:58
Ruby	Rubyタグが付けられた新着投稿 - Qiita	Rubyの配列で複数要素の位置を得る ( index を複数得たい )	https://qiita.com/YumaInaura/items/e6175f623e9f372f0dfa	aarreachindexselectiarrix	2022-09-23 19:54:57
Docker	dockerタグが付けられた新着投稿 - Qiita	【爆速版】Rails環境構築から自動デプロイまで（M1Mac）	https://qiita.com/rexid/items/4ebed3a7c3573cdaa442	mmacdocker	2022-09-23 19:41:51
Docker	dockerタグが付けられた新着投稿 - Qiita	【自動テスト/自動デプロイ】デプロイしたRailsアプリケーションにCI/CDを構築	https://qiita.com/rexid/items/0265e16f11cba57a07cc	docker	2022-09-23 19:16:48
Ruby	Railsタグが付けられた新着投稿 - Qiita	【爆速版】Rails環境構築から自動デプロイまで（M1Mac）	https://qiita.com/rexid/items/4ebed3a7c3573cdaa442	mmacdocker	2022-09-23 19:41:51
Ruby	Railsタグが付けられた新着投稿 - Qiita	【自動テスト/自動デプロイ】デプロイしたRailsアプリケーションにCI/CDを構築	https://qiita.com/rexid/items/0265e16f11cba57a07cc	docker	2022-09-23 19:16:48
海外TECH	MakeUseOf	The 7 Best Mini Drones	https://www.makeuseof.com/best-mini-drones/	controls	2022-09-23 10:30:14
海外TECH	MakeUseOf	What Is a Crypto Dark Pool? Can Normal Traders Use One?	https://www.makeuseof.com/what-is-crypto-dark-pool/	berghain	2022-09-23 10:15:13
海外TECH	MakeUseOf	What Is Tesla's New $250 CCS Adapter & Who Needs to Buy One?	https://www.makeuseof.com/what-is-tesla-ccs-adapter-who-needs-one/	tesla	2022-09-23 10:05:13
海外TECH	DEV Community	AWS APAC Community Summit Wrap up	https://dev.to/aws-heroes/aws-apac-community-summit-wrap-up-1an4		2022-09-23 10:39:48
海外TECH	DEV Community	Create a Simple Stock Price Tracker in Flutter	https://dev.to/hackmamba/create-a-simple-stock-price-tracker-in-flutter-n0h	Create a Simple Stock Price Tracker in FlutterTrackers are mechanisms applications or systems used by investors to track the financial performance of a particular stock They give investors the required leverage to make a profitable financial decision as an individual or a company In this post we will learn how to create a stock price tracker in Flutter using the Marketstack open API to search for our favourite stock details and save the details on Appwrite s database PrerequisitesTo fully grasp the concepts presented in this tutorial we require the following Basic understanding of Dart and FlutterFlutter SDK installedXcode with a developer account for Mac users Either IOS Simulator Android Studio or Chrome web browser to run our applicationDocker installationAn Appwrite instance check out this article on how to set up an instance locally or one click install on DigitalOcean or GitpodMarketstack account Sign up is completely free Getting StartedIn this post we will focus on implementations only The project UI has already been set up To get started we need to clone the project by navigating to the desired directory and running the command below git clone amp amp cd stock trackerThe complete source code is also available on the dev branch of the same repository Running the ProjectFirst we need to install the project dependencies by running the command below flutter pub getThen run the project using the command below flutter runThe command above will run the application on the selected device Creating a New Appwrite ProjectTo create a new project start the Appwrite instance and navigate to the specified hostname and port http localhost Next we need to log into our account or create an account if we don t have one On the console click the Create Project button input stock tracker as the name and click Create Next we need to create a database to save our favourite stocks Navigate to the Database tab click Add Database input stocks as the database name and click Create With that done we need to create a collection for grouping our stocks Click Add Collection input stock list as the collection name and click on Create Appwrite has an advanced yet flexible way to manage access to users teams or roles to specific resources We will modify the permission role all to enable access from any application Then click on Update to save changes Add AttributesAttributes are fields that our database will possess Navigate to the Attributes tab click on Add Attributes add a New String Attribute and size of for name symbol open and exchange fields with the required option marked and click on Create Note The name symbol open and exchange fields represent the name of the stock ticker or symbol of the stock the opening price and the stock marketplace respectively Setting up MarketstackWith that done we need to create an account on Marketstack and get an Access Key to use the open stock API Next we need to navigate to the lib directory and create a utils dart file and add the snippet below class AppConstant marketstack final String accessKey REPLACE WITH ACCESS KEY Connecting Appwrite to FlutterTo add support for our Flutter app navigate to the Home menu click on the Add Platform button and select New Flutter App Depending on the device we are running our Flutter application we can modify it as shown below iOSTo obtain our Bundle ID we can navigate using the path below ios gt Runner xcodeproj gt project pbxprojOpen the project pbxproj file and search for PRODUCT BUNDLE IDENTIFIER Next open the project directory on Xcode open the Runner xcworkspace folder in the app s iOS folder select the Runner project in the Xcode project navigator select the Runner target in the main menu sidebar and then select iOS in the deployment info s target AndroidTo get our package name we can navigate using the path below android gt app gt src gt debug gt AndroidManifest xmlOpen the AndroidManifest xml file and copy the package value Next we need to modify the AndroidManifext xml as shown below lt manifest xmlns android package com example stock tracker gt lt uses permission android name android permission INTERNET gt lt application gt lt activity android name com linusu flutter web auth CallbackActivity android exported true gt lt intent filter android label flutter web auth gt lt action android name android intent action VIEW gt lt category android name android intent category DEFAULT gt lt category android name android intent category BROWSABLE gt lt data android scheme appwrite callback PROJECT ID gt lt intent filter gt lt activity gt lt application gt lt manifest gt Then we need to update the utils dart file as shown below class AppConstant marketstack final String accessKey REPLACE WITH ACCESS KEY appwrite final String databaseId REPLACE WITH DATABASE ID final String projectId REPLACE WITH PROJECT ID final String endpoint REPLACE WITH ENDPOINT final String collectionId REPLACE WITH COLLECTION ID Navigate to the Database menu click on the Stocks database click on the Settings tab and copy the Database ID Switch to the Collections tab click on the stock list collection click on the Settings tab and copy the Collection ID Navigate to the Settings menu to copy the Project ID and API Endpoint For the endpoint property we need to modify it to work with our system s local network address We can adjust accordingly iOSNavigate to the Network section copy the IP address and modify it as shown below class AppConstant marketstack final String accessKey REPLACE WITH ACCESS KEY appwrite final String databaseId REPLACE WITH DATABASE ID final String projectId REPLACE WITH PROJECT ID final String endpoint final String collectionId REPLACE WITH COLLECTION ID AndroidWe can connect our Android emulator to the system s IP using the IP address class AppConstant marketstack final String accessKey REPLACE WITH ACCESS KEY appwrite final String databaseId REPLACE WITH DATABASE ID final String projectId REPLACE WITH PROJECT ID final String endpoint final String collectionId REPLACE WITH COLLECTION ID Building the Stock Price TrackerTo get started we need to create models to convert the response sent from Marketstack and Appwrite to a Dart object The models will also cater to JSON serialization To do this add the snippet below in the same utils dart file class AppConstant code goes here class TickerResponse String name String symbol TickerResponse required this name required this symbol factory TickerResponse fromJson Map lt dynamic dynamic gt json return TickerResponse name json name symbol json symbol class PriceResponse String open String exchange PriceResponse required this open required this exchange factory PriceResponse fromJson Map lt dynamic dynamic gt json return PriceResponse open json open exchange json exchange class Stock String id String name String symbol String open String exchange Stock this id required this name required this symbol required this open required this exchange factory Stock fromJson Map lt dynamic dynamic gt json return Stock id json id name json name symbol json symbol open json open exchange json exchange Map lt dynamic dynamic gt toJson return name name symbol symbol open open exchange exchange The snippet above does the following Creates a TickerResponse PriceResponse and Stock classes with required propertiesAdds a constructor with unrequired and required parametersCreates a fromJson and toJson method for JSON serializationNext we need to create a service file to separate the application core logic from the UI To do this create a stock service dart file inside the lib directory and first update it by doing the following import dart convert import package http http dart as http import package stock tracker utils dart import package appwrite appwrite dart class StockService final accessKey AppConstant accessKey Client client Client Databases db StockService init initialize the application init async client setEndpoint AppConstant endpoint setProject AppConstant projectId db Databases client databaseId AppConstant databaseId get current session Account account Account client try await account get on AppwriteException catch e if e code account createAnonymousSession then value gt value catchError e gt e The snippet above does the following Imports the required dependenciesCreates a StockService class with accessKey client and db properties to connect to Marketstack Appwrite instance and the databaseCreates an init method that configures the Appwrite using the property and also conditionally creates an anonymous user to access the Appwrite databaseFinally we can use the configuration above to create the required methods by updating as shown below imports goes hereclass StockService final accessKey AppConstant accessKey Client client Client Databases db StockService init initialize the application init async init code goes here Future lt TickerResponse gt getTicker String ticker async String tickerKey ticker toUpperCase var response await http get Uri parse tickerKey access key accessKey amp limit var data jsonDecode response body if response statusCode return TickerResponse name data name symbol data symbol else throw Exception Error getting ticker Future lt PriceResponse gt getPrice String ticker async String tickerKey ticker toUpperCase var response await http get Uri parse accessKey amp symbols tickerKey amp limit var data jsonDecode response body if response statusCode return PriceResponse open data data open toString exchange data data exchange else throw Exception Error getting price Future saveStock String ticker async try var tickerDetails await getTicker ticker var priceDetails await getPrice ticker Stock newStock Stock name tickerDetails name symbol tickerDetails symbol open priceDetails open exchange priceDetails exchange var data await db createDocument collectionId AppConstant collectionId documentId unique data newStock toJson return data catch e throw Exception Error creating stock Future lt List lt Stock gt gt getFavStocks async try var data await db listDocuments collectionId AppConstant collectionId var stockList data documents map stock gt Stock fromJson stock data toList return stockList catch e throw Exception Error getting list of products The snippet above does the following Creates a getTicker and getPrice helper methods that use the Marketstack API and Access Key to get stock details and priceCreates a saveStock method that uses the helper methods to get required data and uses the configured database createDocument function to create a stock by passing in the required argumentsCreates a getFavStocks method that uses the configured database s listDocuments function to get a list of stocks and converts the returned JSON to a list using the Stock fromJson methodNote The underscore prefixing variables and functions in Dart marks them as a private entity of a class while the unique flag passed to the createDocument function tells Appwrite to auto generate a unique ID Consuming the ServiceWith that done we can start using the service to perform the required operation Search for Stock and Add to FavouritesTo search for stock and add to favourite we need to navigate to the screens folder open the home dart and modify as shown below import package flutter material dart import package flutter services dart import package stock tracker stock service dart addclass Home extends StatefulWidget override State lt Home gt createState gt HomeState class HomeState extends State lt Home gt final formKey GlobalKey lt FormState gt final TextEditingController ticker TextEditingController bool isLoading false getTickerAndSave setState isLoading true StockService saveStock ticker text then value setState isLoading false ScaffoldMessenger of context showSnackBar const SnackBar content Text Stock saved successfully catchError setState isLoading false ScaffoldMessenger of context showSnackBar const SnackBar content Text Error saving stock override Widget build BuildContext context return Scaffold body Padding padding const EdgeInsets symmetric horizontal vertical child Form key formKey child Column children Column crossAxisAlignment CrossAxisAlignment start children title Column crossAxisAlignment CrossAxisAlignment start children const Text Ticker style TextStyle color Colors grey fontSize const SizedBox height TextFormField validator value if value null value isEmpty return Please input ticker return null inputFormatters LengthLimitingTextInputFormatter controller ticker decoration InputDecoration contentPadding const EdgeInsets symmetric vertical horizontal hintText enter ticker focusedBorder OutlineInputBorder borderRadius BorderRadius circular borderSide const BorderSide color Colors grey enabledBorder OutlineInputBorder borderRadius BorderRadius circular borderSide const BorderSide color Colors grey errorBorder OutlineInputBorder borderRadius BorderRadius circular borderSide const BorderSide color Colors red const SizedBox height SizedBox height width double infinity child TextButton onPressed isLoading null if formKey currentState validate getTickerAndSave style ButtonStyle backgroundColor MaterialStateProperty all lt Color gt Colors blue child const Text Search and Save Stock style TextStyle color Colors white fontWeight FontWeight bold fontSize The snippet above does the following Imports the required dependency Line Creates a ticker and isLoading variable to control input and loading stateLine Creates a getTickerAndSave method that uses the StockService saveStock service to search and save stock set states and uses the snackbar to show the action performedLine Adds the ticker as a controller to manage inputLine Calls the getTickerAndSave method when the search and save button is pressedGet the List of Favourite StocksTo get the list of stocks added as a favourite we need to open the favourite dart file in the same screens folder and modify as shown below import package flutter material dart import package stock tracker stock service dart addimport package stock tracker utils dart addclass Favourites extends StatefulWidget const Favourites Key key super key key override State lt Favourites gt createState gt FavouritesState class FavouritesState extends State lt Favourites gt List lt Stock gt stocks bool isLoading false bool isError false override void initState getFavStockList super initState getFavStockList setState isLoading true StockService getFavStocks then value setState stocks value isLoading false catchError e setState isLoading false isError true Widget build BuildContext context return isLoading const Center child CircularProgressIndicator color Colors blue isError const Center child Text Error loading stocks style TextStyle color Colors red fontWeight FontWeight bold stocks isEmpty const Center child Text No stock added to favourites yet style TextStyle color Colors grey fontWeight FontWeight bold ListView builder itemCount stocks length itemBuilder context index return Container decoration const BoxDecoration border Border bottom BorderSide width color Colors grey padding EdgeInsets fromLTRB child Row mainAxisAlignment MainAxisAlignment spaceEvenly children Expanded flex child Column crossAxisAlignment CrossAxisAlignment start children Text stocks index symbol style TextStyle color Colors black fontWeight FontWeight w SizedBox height Text stocks index name Column crossAxisAlignment CrossAxisAlignment end children Text stocks index open style TextStyle color Colors blue fontWeight FontWeight w SizedBox height Text stocks index exchange The snippet above does the following Imports the required dependencies Line Creates the stocks isLoading and isError properties to manage the application stateLine Creates a getFavStockList method to get the list of stocks added as favourite using the StockService getFavStocks service sets states accordingly and uses the initState method to call the getFavStockList method when the object is inserted into the treeModifies the UI widgets to show the stocks added as favourite coming from AppwriteWith that done we restart the application using the code editor or run the command below flutter runWe can also validate the entries by navigating to the Database section of Appwrite s management console ConclusionThis post discussed how to create a stock price tracker in Flutter and Appwrite The Appwrite platform ships with services that speed up development processes Try it out today and focus on what matters while Appwrite takes care of the tricky part These resources might be helpful Appwrite official documentation Appwrite Flutter SDK Marketstack API Documentation	2022-09-23 10:19:52
海外TECH	DEV Community	Understand call, apply, and bind functions in JavaScript like never before.	https://dev.to/swastikyadav/understand-call-apply-and-bind-functions-in-javascript-like-never-before-575e	Understand call apply and bind functions in JavaScript like never before In this post we ll take a detailed look at how call apply and bind work in JavaScript JavaScript s call apply and bind functions are often misunderstood In this video we ll clear up the confusion once and for all We ll discuss the differences between the three and when you would want to use each one We ll also provide examples to help you understand how they work By the end of this post you ll have a deep understanding of how these functions work and be able to use them in your own code So let s get started Before we go any further there is also a video explanation of this post You can check it out here Now let s start for real Let s say we have an object with name and greet function const obj name Swastik greet age console log Hello this name age age obj greet console gt Hello Swastik age Calling the greeet function consoles Hello Swastik The this keyword refers to the context of greet function In other words this keywords for greet function refers to the object obj in which it was defined Now let s say you need to change the context of greet function means you need to change where the this keyword refers in greet function from obj to obj Let s define obj const obj name Yadav What we want to achieve is that when we call greet function it should console Hello Yadav instead of Hello Swastik This can be achieved with call apply and bind method in JavaScript call call method changes the context of a given function to the context that we specify So here we are changing the context of greet from obj to obj obj greet call obj console gt Hello Yadav age First argument is the new context we want and all comma separated arguments are for greet function apply apply method is exactly similar to call method the only difference being that call takes argument of greet as comma separated and apply takes them as an array obj greet apply obj console gt Hello Yadav age bind bind is also exactly similar to call and apply and here is the difference call and apply executes the fuction right away bind returns a new function binded with new this keyword which can be called later const bindYadav obj greet bind obj bindYadav console log gt Hello Yadav age That s it for this post I hope you found this useful and if so please show your support by sharing this post and following me Master and learn JavaScript like never before	2022-09-23 10:18:37
海外TECH	DEV Community	The simple guide to understanding Callback functions in JavaScript	https://dev.to/efkumah/the-simple-guide-to-understanding-callback-functions-in-javascript-3e3e	The simple guide to understanding Callback functions in JavaScriptFunctions are one of the underlying building blocks in JavaScript It helps us perform a specific task when it is executed In this post we take a look at callback functions with easy to follow explanation and examples By the end of the article you should be able to understand callback functions including both synchronous and asynchronous callback functions Let s get started Understanding functions in JavaScriptBefore we dive into callback function let s revisit function in JavaScriptA function is a block of code that performs a particular task when it is carried out For an operation to qualify as a function it requires a certain input and return an output and there should be a clear relationship between the input and the output To use a function we must define and call it Take a look at the code below define the functionfunction sayHi user console log Hello user callthe functionsayHi Emmanuel In the code above we define the function using the function keyword followed the name of the function sayHi and parameter to the function enclosed in parentheses The statements that will be carried out will then be enclosed in the curly braces Run the function using the name of the function followed by parenthesis The will contain the argument which is the actual data you want to pass to the function The argument is the data inputted Any data we input will be stored in the parameter which serves as a placeholder Finally in the body of the function we run our task and output the required data to the user Function ArgumentsFunction arguments are the actual values passed to and received by the function The argument can be of any data type string objects arrays numbers etc When we pass the required argument to the function it will be stored in the parameter The parameter serves as the placeholder to the actual value to be passed We can then use the parameter in the body of the function to perform some tasks JavaScript allows us to pass a function as an argument to another function and use that function in body of the outer function This approach is what is termed callback function Below we take a dive to understand callback function What is a callback function A callback function is a function that is passed as an argument to another function which is then invoked inside the outer function to complete some kind of routine or action Let s see the code below function firstFunc anotherFunc execute the other function anotherFunc Define our callback functionfunction secondFunc console log I am another function called inside the outer function execute the firstFunc and pass the second function as the argumentfirstFunc secondFunc We can also use arrow function and declare the second function directly in the main function See the code below firstFunc gt console log I am another function called inside the outer function The output I am another function called inside the outer function In the code above we declared two functions firstFunc and secondFunc We run the firstFunc function and pass the secondFunc function as an argument Note that the actual data we are passing to the function is another function declared as secondFuncNow within the body of the firstFunc we can run the secondFunc we declared Because we are passing secondFunc as an argument to the firstFunc the secondFunc becomes our callback functionIf you ve defined a function and you re not invoking it by yourself ーbut rather supply it as an argument to another function ーthen you ve created a callback Passing a function to another function as argument Functions are considered as objects in JavaScript Like objects functions have properties and methods We can assign an object to a variable as well as pass objects as arguments to a function Because we can pass objects as arguments to a function and a function is technically an object we can also pass a function as an argument to another function In the outer function we callback the passed function Using this approach we extend the functionality of our application Example of a callback function Supposing we want to perform specific operations for instance add and multiply two numbers We can simply declare the functions for these tasks as below addNum functionfunction addNum x y return x y multiplyNum functionfunction multNum x y return x y run the addNum and multNum functionconsole log addNum console log multNum The output for these operations will beNow supposing we want to extend this code to output certain statement before performing the operations how will we approach it We can declare a higher order function a function that accepts another function as a parameter and return that function In the body of the higher order function we include the statement to be outputted and the required function to run Let s see how to achieve that Define the higher order function which will include the statement to be outputtedDefine the tasks mathematical operations to be performed in their respective functionsRun the higher order function and pass the actual function to be performed as an argument In the body of the higher order function run the actual function to perform the taskThe code below will be higher order functionfunction operateNum callback x y console log Let s learn some operations using x and y execute the callback function console log callback x y addNum functionfunction addNum x y return Adding x and y gives us x y multiplyNum functionfunction multNum x y return Multiplying x and y gives us x y call the higher order function and a pass it the addNum or multNum function pass the actual numbers to perform the operation on operateNum addNum operateNum multNum In the code above we define the operateNum as the higher order functionWe declared two other functions addNum and multiplyNum which accepts two numbers and perform an addition and multiplication on them respectively We run the operateNum function and then pass either the addNum or multNum function as an argument to it We also pass the operateNum two numbers and as arguments With this approach we will now run the addNum or multNum function only in the operateNum function The addNum or multNum function can accept the two numbers passed to the operateNumBecause we are passing the addNum or multNum as functions to the operateNum the addNum and multNum are referred to as a callback functions We will only call these functions later inside the operateNum function What s important is that the higher order function takes the full responsibility of invoking the callback function later Why do we need a callback function JavaScript runs code synchronously this means every line of code runs line by line from top to down With this approach a statement has to wait for the previous statement to execute before it can run However there are instances where you want a function to run after something else has happened For instance when we request data from a server it takes some time for the response to get to us In such situations we will have to wait for the response before we can move to the next line of code to execute Since waiting for the response could take time our entire application will grind to a halt whiles the data is being fetched from the server This scenario can be avoided when we use callback functions The callback function ensures that a function will run later right after a certain task has been completedThere are two types of callback functions synchronous and asynchronous callback functions Synchronous Callback function The synchronous callback is executed during the execution of the higher order function that uses the callback Let s understand the above using the example below function greetUser name console log Hello name welcome function getUserInput callback const userInput prompt Please enter your name callback userInput execute the higher order functiongetUserInput greetUser console log waiting to run In the code above We pass the greetUser function as an argument to the getUserInput function The greetUser function is our callback function It will be executed later when the getUserInput function is executed We are passing the greetUser function as an argument to the getUserInput function because the greetUser depends on a value from the getUserInput Hence we do not want to execute the greetUser function immediately When thegetUserInput is executed it provides a prompt to enter an input The greetUser function relies on the inputed value once that value is passed to it the greetUser function will also be executed The above is an example of a synchronous callback because the callback function get executed immediately the higher order function is executed Synchronous callback functions are blocking meaning any statement below the higher order function will not be excuted until the higher order function gets executed Run the code snippet above to verify Examples of synchronous callback functionsMost JavaScript built in methods especially the Array methods utilizes synchronous callbacks Any function passed to the desired method will be executed immediately the built in method is run Example of built in JavaScript methods are array map callback array forEach callback array reduce callback etcTake another look at a synchronous callback function using the array filter methodlet numbers const isOdd num gt return num const oddNumbers numbers filter isOdd console log oddNumbers The output of the code will be The isOdd function is passed as an argument to the built in array filter method When the array filter method gets executed we then run the isOdd function Since it is synchronous the console log oddNumbers gets blocked waiting for the numbers filter isOdd to run Asynchronous Callback functionThe asynchronous callback is executed after the execution of the higher order function The higher order function will run first without waiting for the callback function It however ensures to execute the callback eventually on a certain event for instance on a click of a button Asynchronous callbacks are non blocking if there s any code below the higher order function it doesn t wait untill the the callback function completes before that code runs Take a look at the code below console log start set timeout setTimeout function callLater console log I will run later console log end set timeout In the code above callLater is an asynchronous callback function because the higher order functionsetTimeout callLater starts and completes its execution However callLater function is executed after seconds Because aynchronous callback functions are non blocking the code below the setTimeout function which is console log end set timeout will still run whiles the callback function is in progress To verify check the output of the code below start set timeout end set timeout I will run later Example Executing a callback function on eventJavaScript is an event driven programming language hence we can executecallback functions when an event occurs for instance when a user clicks on a button Let s take another look at an asynchronous callback function In the code below we run the handleClick callback function only when the button element has been clicked index html lt DOCTYPE html gt lt html gt lt head gt lt meta charset utf gt lt meta name viewport content width device width gt lt title gt JS Bin lt title gt lt head gt lt body gt lt button id btn gt Click me lt button gt lt body gt lt html gt index jsconst myBtn document getElementById btn myBtn addEventListener click function handleClick console log btn clicked console log non blocking so i will run In the code aboveWe selected a button element with and id of btn from the html and assign it to the myBtn variableWe attached an addEventListener function to the myBtn elementThe addEventListener is a higher order function which listens for a click event We pass the handleClick function as a callback function to the higher order function When the code is executed the addEventListener function will execute first and then listen for click on the button element Eventually on a click on the button the handleClick callback function will be executed after the execution of the higher order function Because asychronous callback functions are non blocking the code below the addEventLister method will run whiles the handleClick function is waiting to execute The output of the code above is non blocking so i will run btn clicked Asynchronicity means that if JavaScript has to wait for an operation to complete it will execute the rest of the code while waiting SummaryLet s recap what we have learnt A high order function is a function that accepts another function as an argument A callback function is a function passed into another function as an argument to be executed laterA callback function ensures that a function will not run when a task is in progress for instance fetching data from an api but will only run right after the task has been completedThere are two type of callback functions synchronous and asynchronous callback functonsIf you have found this article useful give me thumps up It motivates me to keep writing more If you have any questions or comment feel free to let me know Please do share this article on your social media channel it might help someone becomes a better developer Let s connect on Twitter	2022-09-23 10:07:34
Apple	AppleInsider - Frontpage News	The best alternatives to Apple Arcade	https://appleinsider.com/inside/apple-arcade/best/the-best-alternatives-to-apple-arcade?utm_medium=rss	The best alternatives to Apple ArcadeApple Arcade has a particular market segment that it is targeting ーbut there are better options for other game types These are the best streaming game services that you can play on your favorite Apple devices After you ve worked through the Apple Arcade catalog you might want to expand your gaming horizons Here are some alternatives to Apple Arcade currently available for iPhone and iPad Xbox Game Pass Ultimate Read more	2022-09-23 10:58:13
Apple	AppleInsider - Frontpage News	Apple Music sponsoring NFL's Super Bowl half-time show	https://appleinsider.com/articles/22/09/23/nfl-apple-music?utm_medium=rss	Apple Music sponsoring NFL x s Super Bowl half time showBack in the s Apple poached John Sculley from Pepsi Now for Apple Music is replacing the soft drink firm as sponsor of what the NFL claims is the most watched musical performance of the year In February Pepsi pulled out of sponsoring the halftime show though it will continue to sponsor the NFL NBC Sports reported then that the NFL was looking for a replacement willing to sponsor the show for between million and million per year Now while it has not disclosed any of the terms of the deal the NFL has announced that Apple Music will sponsor the minute show Read more	2022-09-23 10:04:47
海外ニュース	Japan Times latest articles	ANA to increase international flights as Japan’s borders fully reopen	https://www.japantimes.co.jp/news/2022/09/23/business/ana-boost-flights-border-reopen/	ANA to increase international flights as Japan s borders fully reopenCOVID hit Japan s tourism industry hard ーthere were only about foreign visitors last year compared with a record million in	2022-09-23 19:23:26
ニュース	BBC News - Home	Income tax to be cut by 1p from April	https://www.bbc.co.uk/news/business-63007219?at_medium=RSS&at_campaign=KARANGA	income	2022-09-23 10:38:36
ニュース	BBC News - Home	Wolf Hall author Hilary Mantel dies aged 70	https://www.bbc.co.uk/news/entertainment-arts-63007307?at_medium=RSS&at_campaign=KARANGA	trilogy	2022-09-23 10:45:30
ニュース	BBC News - Home	Silvio Berlusconi: Ex-PM defends Russian war on eve of Italian election	https://www.bbc.co.uk/news/world-europe-63005402?at_medium=RSS&at_campaign=KARANGA	decent	2022-09-23 10:20:48
ニュース	BBC News - Home	At a glance: What's in the mini-budget?	https://www.bbc.co.uk/news/business-62920969?at_medium=RSS&at_campaign=KARANGA	stamp	2022-09-23 10:23:32
ニュース	BBC News - Home	Chancellor Kwasi Kwarteng hails 'new era' as he unveils tax cuts	https://www.bbc.co.uk/news/uk-politics-63005302?at_medium=RSS&at_campaign=KARANGA	economic	2022-09-23 10:34:47
ニュース	BBC News - Home	Stamp duty cut in bid to help house buyers	https://www.bbc.co.uk/news/business-63005427?at_medium=RSS&at_campaign=KARANGA	buyers	2022-09-23 10:26:08
ニュース	BBC News - Home	Stamp duty: What is it and how much do I pay?	https://www.bbc.co.uk/news/business-53319433?at_medium=RSS&at_campaign=KARANGA	rules	2022-09-23 10:41:56
ニュース	BBC News - Home	National Insurance: Will tax cut save me money?	https://www.bbc.co.uk/news/uk-politics-58436009?at_medium=RSS&at_campaign=KARANGA	insurance	2022-09-23 10:20:05
ニュース	BBC News - Home	Rugby World Cup: Flying England economy to NZ a "challenging decision", says RFU	https://www.bbc.co.uk/sport/rugby-union/63006512?at_medium=RSS&at_campaign=KARANGA	Rugby World Cup Flying England economy to NZ a quot challenging decision quot says RFUFlying England in economy class to the World Cup in New Zealand is described as a challenging decision by the Rugby Football Union	2022-09-23 10:54:25
ニュース	BBC News - Home	Raducanu beats Linette in dominant display to reach Korea Open semi-finals	https://www.bbc.co.uk/sport/tennis/63006853?at_medium=RSS&at_campaign=KARANGA	magda	2022-09-23 10:37:28
北海道	北海道新聞	骨片３個新たに発見　知床集中捜索で道警　沈没現場から５キロ	https://www.hokkaido-np.co.jp/article/735399/	知床半島	2022-09-23 19:18:39
北海道	北海道新聞	東海道新幹線が運転見合わせ　愛知で雨量規制値超える	https://www.hokkaido-np.co.jp/article/735403/	愛知県豊橋市	2022-09-23 19:19:00
北海道	北海道新聞	５０歳の宮本が単独首位　男子ゴルフ第２日	https://www.hokkaido-np.co.jp/article/735374/	兵庫県小野	2022-09-23 19:01:44
北海道	北海道新聞	玉木氏、中ロに「頑張って」　円安対策巡り失言	https://www.hokkaido-np.co.jp/article/735400/	国民民主党	2022-09-23 19:16:00
北海道	北海道新聞	五輪ぬいぐるみ販売　元理事に数百万円提供か　東京地検が捜査	https://www.hokkaido-np.co.jp/article/735382/	東京五輪	2022-09-23 19:10:57
北海道	北海道新聞	村田兆治容疑者を逮捕　元プロ野球選手、暴行容疑	https://www.hokkaido-np.co.jp/article/735391/	村田兆治	2022-09-23 19:06:00
北海道	北海道新聞	クデルメトワ、張帥が準決勝へ　東レ・テニス第５日	https://www.hokkaido-np.co.jp/article/735397/	女子テニス	2022-09-23 19:09:00
北海道	北海道新聞	宗谷管内１６人感染　留萌管内は１９人　新型コロナ	https://www.hokkaido-np.co.jp/article/735396/	宗谷管内	2022-09-23 19:09:00
北海道	北海道新聞	国葬、自宅前で儀仗隊見送り検討　遺骨乗せた車、防衛省経由も	https://www.hokkaido-np.co.jp/article/735394/	安倍晋三	2022-09-23 19:07:00