← flaviocopes.com

Posts tagged "JavaScript"

Jan 21 2023 js	js	JavaScript, how to remove multiple line breaks
Jan 14 2023 js	js	How to get retrieve all results of a regex with capturing groups in JS
Jan 13 2023 js	js	A regular expression to capture a URL without query string parameters
Jan 12 2023 js	js	Getting year-month-date from JS dates
Jan 09 2023 js	js	Slugify a string in JavaScript
Dec 29 2022 js	js	How to clone anything in JavaScript
Nov 27 2022 js	js	What's the best JavaScript course?
Sep 23 2022 js	js	How to add leading zero to a number in JavaScript
Jul 27 2022 js	js	How to await in a loop in JavaScript
Jul 24 2022 js	js	JavaScript, how to get string until character
Jul 11 2022 js	js	How to redirect to a new URL using JavaScript
Jun 02 2022 js	js	Fix uploading files using fetch and multipart/form-data
May 24 2022 js	js	How to change image URLs in a markdown string
May 18 2022 js	js	How to fix an issue installing Node `canvas` on macOS
May 14 2022 js	js	How to dynamically import JavaScript modules
May 09 2022 js	js	How to fix the "Parse failure: Unterminated string constant" error
May 04 2022 js	js	How to solve the document is not defined error
Apr 29 2022 js	js	JavaScript, how to get the class name of an object
Apr 25 2022 js	js	How to fix decimals arithmetic in JavaScript
Apr 16 2022 js	js	How to fix tsconfig.json "No inputs were found in config file" error
Apr 09 2022 js	js	How to add days to a date in JavaScript
Feb 08 2022 js	js	How to debug JavaScript code
Nov 15 2021 js	js	How I built a dashboard for the iPad with JavaScript
Sep 10 2021 js	js	The hardest concepts to understand in JavaScript
Jul 25 2021 js	js	How to conditionally load data with SWR
Jul 24 2021 js	js	How to use SWR
Jul 20 2021 js	js	How to copy the properties of an inner object to the outer
Jul 05 2021 js	js	TypeScript, disable checks for `declared but its value is never read`
Jun 21 2021 js	js	How to convert a callback into async/await
May 12 2021 js	js	How to solve the `TypeError: Attempted to assign to readonly property` error
Apr 30 2021 js	js	Johnny Five, receiving input from the device
Apr 29 2021 js	js	Johnny Five, how to use a REPL
Apr 28 2021 js	js	Johnny Five, how to work with an LCD Screen
Apr 27 2021 js	js	Johnny Five, how to light a LED
Apr 13 2021 js	js	Johnny Five Tutorial
Apr 08 2021 js	js	How to use window.confirm()
Apr 07 2021 js	js	How to use window.prompt()
Feb 05 2021 js	js	Wait for all promises to resolve in JavaScript
Nov 25 2020 js	js	JavaScript Algorithms: Bubble Sort
Nov 24 2020 js	js	JavaScript Algorithms: Merge Sort
Nov 23 2020 js	js	JavaScript Algorithms: Quicksort
Nov 22 2020 js	js	JavaScript Algorithms: Selection Sort
Nov 21 2020 js	js	JavaScript Algorithms: Binary Search
Nov 20 2020 js	js	JavaScript Algorithms: Linear Search
Nov 18 2020 js	js	JavaScript, how to replace an item of an array
Nov 16 2020 js	js	JavaScript, how to find duplicates in an array
Nov 15 2020 js	js	JavaScript, how to extend a class
Nov 14 2020 js	js	JavaScript, how to filter an array
Nov 13 2020 js	js	JavaScript, how to find a character in a string
Nov 12 2020 js	js	JavaScript, how to exit a function
Nov 11 2020 js	js	JavaScript, how to export multiple functions
Nov 10 2020 js	js	JavaScript, how to export a function
Nov 09 2020 js	js	JavaScript Data Structures: Linked lists
Nov 06 2020 js	js	JavaScript Data Structures: Queue
Oct 31 2020 js	js	The Stack JavaScript Data Structure
Oct 30 2020 js	js	The Array JavaScript Data Structure
Oct 25 2020 js	js	How to destructure an object to existing variables in JavaScript
Aug 23 2020 js	js	How to test for an empty object in JavaScript
Aug 19 2020 js	js	How to get the index of an item in a JavaScript array
Aug 15 2020 js	js	Gatsby, fix the "cannot find module gatsby-cli/lib/reporter" error
Aug 11 2020 js	js	How to add an item at the beginning of an array in JavaScript
Aug 10 2020 js	js	How I fixed a "cb.apply is not a function" error while using Gitbook
Aug 09 2020 js	js	How to swap two array elements in JavaScript
Jul 23 2020 js	js	How to handle promise rejections
Jul 03 2020 js	js	Chaining method calls in JavaScript
Jul 02 2020 js	js	A curious usage of commas in JavaScript
Jul 01 2020 js	js	Namespaces in JavaScript
Jun 29 2020 js	js	Custom errors in JavaScript
Jun 28 2020 js	js	Custom events in JavaScript
Jun 27 2020 js	js	Are values passed by reference or by value in JavaScript?
Jun 26 2020 js	js	Introduction to XState
Jun 25 2020 js	js	The JavaScript super keyword
Jun 24 2020 js	js	Event delegation in the browser using vanilla JavaScript
Jun 23 2020 js	js	JavaScript Proxy Objects
Jun 22 2020 js	js	How to accept unlimited parameters in a JavaScript function
Jun 21 2020 js	js	How to check if a value is a number in JavaScript
Jun 20 2020 js	js	How to reverse a JavaScript array
Jun 19 2020 js	js	The importance of timing when working with the DOM
Jun 18 2020 js	js	How to change commas into dots with JavaScript
Jun 16 2020 js	js	What is hoisting in JavaScript?
Jun 15 2020 js	js	What is object destructuring in JavaScript?
Jun 14 2020 js	js	The JavaScript for..of loop
Jun 13 2020 js	js	What are the ways we can break out of a loop in JavaScript?
Jun 12 2020 js	js	What's the difference between a method and a function?
Jun 11 2020 js	js	What is the difference between null and undefined in JavaScript?
Jun 10 2020 js	js	In which ways can we access the value of a property of an object?
Jun 08 2020 js	js	Arrow functions vs regular functions in JavaScript
Jun 07 2020 js	js	How to return multiple values from a function in JavaScript
Jun 06 2020 js	js	How can you tell what type a value is, in JavaScript?
Jun 05 2020 js	js	Primitive types vs objects in JavaScript
Jun 02 2020 js	js	DOM events: stopPropagation vs preventDefault() vs. return false
Jun 01 2020 js	js	Event bubbling and event capturing
May 31 2020 js	js	How to check if a key exists in a JavaScript object
May 30 2020 js	js	How to shuffle elements in a JavaScript array
May 28 2020 js	js	How to get the last segment of a path or URL using JavaScript
May 12 2020 js	js	The Deno Handbook: a concise introduction to Deno 🦕
May 11 2020 js	js	Object destructuring with types in TypeScript
May 09 2020 js	js	How to detect if an Adblocker is being used with JavaScript
May 08 2020 js	js	Parcel, how to fix the `regeneratorRuntime is not defined` error
May 06 2020 js	js	How to detect dark mode using JavaScript
May 04 2020 js	js	Loading an external JS file using Gatsby
May 02 2020 js	js	Gatsby, how to change the favicon
May 01 2020 js	js	How to solve the "is not a function" error in JavaScript
Apr 30 2020 js	js	How to force credentials to every Axios request
Apr 27 2020 js	js	How to check if an element is a descendant of another
Apr 26 2020 js	js	How to create an exit intent popup
Apr 23 2020 js	js	How to fix the TypeError: Cannot assign to read only property 'exports' of object '#<Object>' error
Apr 21 2020 js	js	How to remove the first character of a string in JavaScript
Apr 20 2020 js	js	How to remove the last character of a string in JavaScript
Apr 19 2020 js	js	How to write text into to an HTML canvas
Apr 18 2020 js	js	How to divide an array in half in JavaScript
Apr 17 2020 js	js	How to cut a string into words in JavaScript
Apr 16 2020 js	js	How to load an image in an HTML canvas
Apr 15 2020 js	js	How to slow down a loop in JavaScript
Apr 10 2020 js	js	How to divide an array in multiple equal parts in JS
Apr 09 2020 js	js	How to get the first n items in an array in JS
Apr 08 2020 js	js	The same POST API call in various JavaScript libraries
Mar 25 2020 js	js	Let vs Const in JavaScript
Mar 12 2020 js	js	How to remove duplicates from a JavaScript array
Mar 11 2020 js	js	How to remove all the node_modules folders content
Mar 09 2020 js	js	How to convert an Array to a String in JavaScript
Mar 03 2020 js	js	List of keywords and reserved words in JavaScript
Jan 18 2020 js	js	How to send the authorization header using Axios
Dec 31 2019 js	js	This decade in JavaScript
Dec 10 2019 js	js	How to flatten an array in JavaScript
Dec 09 2019 js	js	JavaScript Nullish Coalescing
Dec 03 2019 js	js	How to replace white space inside a string in JavaScript
Nov 09 2019 js	js	JavaScript Optional Chaining
Nov 08 2019 js	js	JavaScript Dynamic Imports
Nov 05 2019 js	js	How to use top-level await in JavaScript
Nov 04 2019 js	js	How to calculate the number of days between 2 dates in JavaScript
Nov 02 2019 js	js	How to iterate over object properties in JavaScript
Nov 01 2019 js	js	How to format a date in JavaScript
Oct 30 2019 js	js	How to upload a file using Fetch
Oct 26 2019 js	js	How to get the days between 2 dates in JavaScript
Oct 25 2019 js	js	How to wait for 2 or more promises to resolve in JavaScript
Oct 23 2019 js	js	JavaScript labeled statements
Oct 16 2019 js	js	How to check if a date refers to a day in the past in JavaScript
Oct 12 2019 js	js	How to check if two dates are the same day in JavaScript
Oct 11 2019 js	js	How to get the month name from a JavaScript date
Oct 10 2019 js	js	How to get yesterday's date using JavaScript
Oct 09 2019 js	js	How to get tomorrow's date using JavaScript
Oct 04 2019 js	js	How to send urlencoded data using Axios
Sep 26 2019 js	js	How to get last element of an array in JavaScript?
Sep 25 2019 js	js	How to check if a JavaScript value is an array?
Sep 23 2019 js	js	How to join two arrays in JavaScript
Sep 22 2019 js	js	How to join two strings in JavaScript
Sep 21 2019 js	js	Links used to activate JavaScript functions
Sep 20 2019 js	js	What's the difference between using let and var in JavaScript?
Sep 14 2019 js	js	Why you should not modify a JavaScript object prototype
Sep 13 2019 js	js	How to add item to an array at a specific index in JavaScript
Sep 11 2019 js	js	How to break out of a for loop in JavaScript
Sep 10 2019 js	js	How to check if an object is empty in JavaScript
Sep 09 2019 js	js	How to return the result of an asynchronous function in JavaScript
Sep 06 2019 js	js	Is JavaScript still worth learning?
Sep 02 2019 js	js	== vs === equal operators in JavaScript, what's the difference?
Sep 01 2019 js	js	What does the double negation operator !! do in JavaScript?
Aug 29 2019 js	js	How to check if a JavaScript array contains a specific value
Aug 26 2019 js	js	How to check types in JavaScript without using TypeScript
Aug 24 2019 js	js	How to rename fields when using object destructuring
Jul 28 2019 js	js	How to use the JavaScript bcrypt library
Jul 26 2019 js	js	JavaScript Symbols
Jul 15 2019 js	js	JavaScript Public Class Fields
Jul 14 2019 js	js	How to sort an array by date value in JavaScript
Jul 09 2019 js	js	JavaScript Private Class Fields
Jul 08 2019 js	js	How to add an event listener to multiple elements in JavaScript
Jul 07 2019 js	js	How to get the value of a CSS property in JavaScript
Jul 06 2019 js	js	JavaScript Operators
Jun 29 2019 js	js	The JavaScript `in` operator
Jun 24 2019 js	js	The JavaScript reduce() Function
Jun 23 2019 js	js	The JavaScript map() Function
Jun 22 2019 js	js	The JavaScript filter() Function
Jun 21 2019 js	js	The JavaScript Global Object
Jun 20 2019 js	js	JavaScript Error Objects
Jun 18 2019 js	js	JavaScript Object Properties
Jun 17 2019 js	js	JavaScript Recursion
Jun 15 2019 js	js	JavaScript Ternary Operator
Jun 10 2019 js	js	JavaScript Logical Operators
Jun 09 2019 js	js	JavaScript Return Values
Jun 08 2019 js	js	The JavaScript Spread Operator
Jun 06 2019 js	js	JavaScript Function Parameters
Jun 05 2019 js	js	The JavaScript delete Operator
Jun 03 2019 js	js	The JavaScript Switch Conditional
Jun 01 2019 js	js	The JavaScript if/else conditional
May 31 2019 js	js	JavaScript Equality Operators
May 30 2019 js	js	JavaScript Type Conversions (casting)
May 24 2019 js	js	JavaScript Scope
May 21 2019 js	js	JavaScript Statements
May 18 2019 js	js	JavaScript instanceof Operator
May 13 2019 js	js	JavaScript Operators Precedence Rules
May 10 2019 js	js	JavaScript Comparison Operators
May 05 2019 js	js	JavaScript new Operator
May 01 2019 js	js	JavaScript typeof Operator
Apr 30 2019 js	js	JavaScript Internationalization
Apr 28 2019 js	js	JavaScript Assignment Operator
Apr 23 2019 js	js	JavaScript Reference: Object
Apr 22 2019 js	js	The Object valueOf() method
Apr 21 2019 js	js	The Object toString() method
Apr 20 2019 js	js	The Object toLocaleString() method
Apr 19 2019 js	js	The Object propertyIsEnumerable() method
Apr 18 2019 js	js	The Object isPrototypeOf() method
Apr 17 2019 js	js	The Object hasOwnProperty() method
Apr 16 2019 js	js	The Object values() method
Apr 15 2019 js	js	The Object setPrototypeOf() method
Apr 14 2019 js	js	The Object seal() method
Apr 13 2019 js	js	The Object preventExtensions() method
Apr 12 2019 js	js	The Object keys() method
Apr 11 2019 js	js	The Object isSealed() method
Apr 10 2019 js	js	The Object isFrozen() method
Apr 09 2019 js	js	The Object isExtensible() method
Apr 08 2019 js	js	The Object is() method
Apr 07 2019 js	js	The Object getPrototypeOf() method
Apr 06 2019 js	js	The Object getOwnPropertySymbols() method
Apr 05 2019 js	js	The Object getOwnPropertyNames() method
Apr 04 2019 js	js	The Object getOwnPropertyDescriptors() method
Apr 03 2019 js	js	The Object getOwnPropertyDescriptor() method
Apr 02 2019 js	js	The Object freeze() method
Apr 01 2019 js	js	The Object entries() method
Mar 31 2019 js	js	The Object defineProperty() method
Mar 30 2019 js	js	The Object defineProperties() method
Mar 29 2019 js	js	The Object create() method
Mar 28 2019 js	js	The Object assign() method
Mar 27 2019 js	js	JavaScript Property Descriptors
Mar 26 2019 js	js	JavaScript Reference: Number
Mar 25 2019 js	js	The Number isFinite() method
Mar 24 2019 js	js	The Number toFixed() method
Mar 23 2019 js	js	The Number toLocaleString() method
Mar 22 2019 js	js	The Number toExponential() method
Mar 21 2019 js	js	The Number toPrecision() method
Mar 20 2019 js	js	The Number valueOf() method
Mar 19 2019 js	js	The Number toString() method
Mar 18 2019 js	js	The Number parseInt() method
Mar 17 2019 js	js	The Number parseFloat() method
Mar 16 2019 js	js	The Number isSafeInteger() method
Mar 15 2019 js	js	The Number isNaN() method
Mar 14 2019 js	js	The Number isInteger() method
Mar 13 2019 js	js	JavaScript Reference: String
Mar 12 2019 js	js	The String valueOf() method
Mar 11 2019 js	js	Memoization in JavaScript
Mar 11 2019 js	js	The String trimStart() method
Mar 10 2019 js	js	The String trimEnd() method
Mar 09 2019 js	js	The String trim() method
Mar 08 2019 js	js	The String toUpperCase() method
Mar 07 2019 js	js	The String toString() method
Mar 06 2019 js	js	The String toLowerCase() method
Mar 05 2019 js	js	The String toLocaleUpperCase() method
Mar 04 2019 js	js	The String toLocaleLowerCase() method
Mar 03 2019 js	js	The String substring() method
Mar 02 2019 js	js	The String startsWith() method
Mar 01 2019 js	js	The String split() method
Feb 28 2019 js	js	The String slice() method
Feb 27 2019 js	js	The String repeat() method
Feb 26 2019 js	js	The String padStart() method
Feb 25 2019 js	js	The String padEnd() method
Feb 24 2019 js	js	The String normalize() method
Feb 23 2019 js	js	The String match() method
Feb 22 2019 js	js	The String localeCompare() method
Feb 21 2019 js	js	The String lastIndexOf() method
Feb 20 2019 js	js	The String indexOf() method
Feb 19 2019 js	js	The String includes() method
Feb 18 2019 js	js	The String endsWith() method
Feb 17 2019 js	js	The String concat() method
Feb 16 2019 js	js	The String codePointAt() method
Feb 15 2019 js	js	The String charCodeAt() method
Feb 14 2019 js	js	The String charAt() method
Feb 13 2019 js	js	The ES2019 Guide
Feb 13 2019 js	js	How I run little JavaScript snippets
Feb 12 2019 js	js	The String search() method
Feb 11 2019 js	js	The String replace() method
Feb 04 2019 js	js	How to list all methods of an object in JavaScript
Jan 31 2019 js	js	How to solve the unexpected identifier error when importing modules in JavaScript
Jan 30 2019 js	js	The node_modules folder size is not a problem. It's a privilege
Jan 29 2019 js	js	JavaScript Generators Tutorial
Jan 22 2019 js	js	Casting in JavaScript
Jan 21 2019 js	js	How to style DOM elements using JavaScript
Jan 20 2019 js	js	Loosely typed vs strongly typed languages
Jan 19 2019 js	js	Passing undefined to JavaScript Immediately-invoked Function Expressions
Jan 12 2019 js	js	Dynamically select a method of an object in JavaScript
Jan 11 2019 js	js	TypeScript Tutorial
Jan 07 2019 js	js	The definitive guide to debugging JavaScript
Jan 04 2019 js	js	Destructuring Objects and Arrays in JavaScript
Jan 03 2019 js	js	Work with objects and arrays using Rest and Spread
Jan 02 2019 js	js	Introduction to PeerJS, the WebRTC library
Dec 10 2018 js	js	call() and apply() in JavaScript
Dec 07 2018 js	js	How to count the number of properties in a JavaScript object
Dec 06 2018 js	js	How to sort an array of objects by a property value in JavaScript
Dec 05 2018 js	js	How to set default parameter values in JavaScript
Dec 04 2018 js	js	How to encode a URL with JavaScript
Dec 03 2018 js	js	How to empty a JavaScript array
Nov 30 2018 js	js	How to merge two objects in JavaScript
Nov 20 2018 js	js	How to hide a DOM element using plain JavaScript
Nov 19 2018 js	js	Should you use or learn jQuery in 2020?
Nov 15 2018 js	js	The JSONP Guide
Nov 14 2018 js	js	Introduction to JSON
Nov 12 2018 js	js	An introduction to WebAssembly
Nov 11 2018 js	js	What is a Single Page Application?
Nov 07 2018 js	js	How to get the index of an iteration in a for-of loop in JavaScript
Nov 04 2018 js	js	HTML Canvas API Tutorial
Oct 20 2018 js	js	How to generate a random number between two numbers in JavaScript
Oct 16 2018 js	js	Async vs sync code
Oct 11 2018 js	js	How to use Async and Await with Array.prototype.map()
Oct 03 2018 js	js	The ES2018 Guide
Oct 02 2018 js	js	The ES2017 Guide
Oct 02 2018 js	js	How to initialize a new array with values in JavaScript
Oct 01 2018 js	js	The ES2016 Guide
Oct 01 2018 js	js	How to get the current URL in JavaScript
Sep 30 2018 js	js	The ES6 Guide
Sep 30 2018 js	js	How to create a multiline string in JavaScript
Sep 29 2018 js	js	How to check if a string starts with another in JavaScript
Sep 28 2018 js	js	How to get the unique properties of a set of objects in a JavaScript array
Sep 27 2018 js	js	How to validate an email address in JavaScript
Aug 02 2018 js	js	Quotes in JavaScript
Aug 01 2018 js	js	The JavaScript Cookbook
Jul 26 2018 js	js	How to use JavaScript Classes
Jul 25 2018 js	js	JavaScript Exceptions
Jul 24 2018 js	js	JavaScript Prototypal Inheritance
Jul 23 2018 js	js	How to make your JavaScript functions sleep
Jul 21 2018 js	js	Generate random and unique strings in JavaScript
Jul 18 2018 js	js	The JavaScript Math library
Jul 17 2018 js	js	The JavaScript Arithmetic operators
Jul 16 2018 js	js	Semicolons in JavaScript
Jul 08 2018 js	js	A Moment.js tutorial
Jul 07 2018 js	js	The definitive guide to JavaScript Dates
Jul 06 2018 js	js	How to inspect a JavaScript object
Jul 05 2018 js	js	How to trim the leading zero in a number in JavaScript
Jul 03 2018 js	js	A quick reference guide to Modern JavaScript Syntax
Jul 02 2018 js	js	How to replace all occurrences of a string in JavaScript
Jun 28 2018 js	js	The V8 JavaScript Engine
Jun 18 2018 js	js	JavaScript Asynchronous Programming and Callbacks
Jun 14 2018 js	js	Introduction to CommonJS
Jun 13 2018 js	js	Introduction to ES Modules
May 26 2018 js	js	How to check if a JavaScript object property is undefined
May 25 2018 js	js	How to append an item to an array in JavaScript
May 22 2018 js	js	How to remove a property from a JavaScript object
May 21 2018 js	js	How to redirect to another web page using JavaScript
May 20 2018 js	js	JavaScript Immediately-invoked Function Expressions (IIFE)
May 19 2018 js	js	JavaScript Strict Mode
May 18 2018 js	js	How to get the current timestamp in JavaScript
May 16 2018 js	js	this in JavaScript
May 14 2018 js	js	How to convert a string to a number in JavaScript
May 13 2018 js	js	How to format a number as a currency value in JavaScript
May 09 2018 js	js	How to uppercase the first letter of a string in JavaScript
May 08 2018 js	js	Unicode in JavaScript
May 07 2018 js	js	Introduction to Unicode and UTF-8
May 05 2018 js	js	How to deep clone a JavaScript object
May 02 2018 js	js	How to remove an item from an Array in JavaScript
May 01 2018 js	js	How to check if a string contains a substring in JavaScript
Apr 30 2018 js	js	How to use JavaScript Regular Expressions
Apr 29 2018 js	js	A tutorial to JavaScript Arrow Functions
Apr 23 2018 js	js	JavaScript Closures explained
Apr 21 2018 js	js	The JavaScript Glossary
Apr 19 2018 js	js	JavaScript Functions
Apr 18 2018 js	js	The JavaScript Event Loop
Apr 13 2018 js	js	Write JavaScript loops using map, filter, reduce and find
Apr 11 2018 js	js	JavaScript Loops
Apr 10 2018 js	js	JavaScript Events Explained
Mar 31 2018 js	js	Discover JavaScript Timers
Mar 17 2018 js	js	JavaScript Expressions
Mar 16 2018 js	js	Roadmap to Learn JavaScript
Mar 15 2018 js	js	A guide to JavaScript Template Literals
Mar 03 2018 js	js	The Set JavaScript Data Structure
Mar 02 2018 js	js	The Map JavaScript Data Structure
Mar 01 2018 js	js	JavaScript Loops and Scope
Feb 26 2018 js	js	How to use async/await in JavaScript
Feb 23 2018 js	js	An introduction to Functional Programming with JavaScript
Feb 19 2018 js	js	A list of sample Web App Ideas
Feb 15 2018 js	js	JavaScript Variables
Feb 14 2018 js	js	JavaScript Types
Feb 12 2018 js	js	The Lexical Structure of JavaScript
Feb 09 2018 js	js	How to use promises in JavaScript
Feb 01 2018 js	js	The Complete ECMAScript 2015-2019 Guide
Jan 26 2018 js	js	Introduction to the JavaScript Programming Language
Aug 24 2017 js	js	An introduction to JavaScript Arrays
Jan 11 2014 js	js	JavaScript Coding Style
Oct 25 2013 js	js	How to upload files to the server using JavaScript
Sep 15 2013 js	js	Deferreds and Promises in JavaScript (+ Ember.js example)
Jul 16 2012 js	js	Things to avoid in JavaScript (the bad parts)