Med Java - java-script

ajax-fetch

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Ajax fetch example AJAX (Asynchronous JavaScript and XML) and async JavaScript both deal with asynchronous behavior in JavaScript, but they are used for different things. AJAX is a technique that allows a web page to communicate with a server and update its content without refreshing the page. AJAX can be done using vanilla JavaScript (usually with the

arrow-function-implicit-return

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Arrow Functions Implicit Return Arrow functions allow for a concise syntax that can include an implicit return. Syntax: const functionName = (parameters) => expression; The expression right after the => will be implicitly returned. This is particularly useful for simple, one-liner functions.

arrow-function-return-object

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Returning an Object from an arrow function If you want to return the object from the arrow function, you'll need to either use the return keyword: const getObject = () => { return { key: 'value' }; }; Or use parentheses to make it an implicit return of an object literal:

babel

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Babel Use cases Babel was mainly used to transpile (compile) ES6 code into ES5 or older version of ES (ECMAScript). Latest versions of Node.js (for example 16.15.1) already has good support for ES6, so babel may not be needed. But, there are still situations where using Babel can be beneficial:

bitwise-or-bitwise-and-ternary-optional-chaining-operators

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script | Bitwise OR, ^ Bitwise XOR, & Bitwise AND, ? Ternary Conditional Operator and ?. Optional Chaining Operator In JavaScript, there are the | (bitwise OR) and & (bitwise AND) operators, which are different from || and &&. These operators perform bitwise operations, which means

closures

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Closures A closure is a function that remembers the variables and scope of its outer (enclosing) function, even after the outer function has finished executing. It “closes over” the variables it needs, hence the name “closure.”

console-table-error-assert-group

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Console Error, Table, Assert, Group Console table Along with console.log, console.info, console.warn and console.error, there is console.table which is very useful to print data in a tabular format (for objects, arrays and arrays of objects).

double-not-operator

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

!! Double not operator The double NOT operator (!!) in JavaScript is a bit of a trick that converts any value to its corresponding boolean value. How it works: * The first ! negates the value, converting it to its opposite boolean value. If the original value is truthy, this results in

dynamic-function-invocation

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Dynamic Function Invocation The object[method](...) syntax is a common pattern in JavaScript that allows you to dynamically call a method on an object using a variable for the method name. This pattern can be useful in various scenarios where you need to

falsy-truthy-values

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Falsy and Truthy Values Falsy values A falsy value is a value considered false if it's encountered in a boolean context. These are the falsy values: * false: The keyword false itself is obviously considered falsy. * 0, -0, 0n, -0n: The number zero (including its negative counterpart and big int) is considered falsy.

fetch-using-async-await

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Fetch using async/await Introduction Async/Await is part of the ES2017 specification and provides a more streamlined syntax for dealing with promises, leading to cleaner, easier-to-read code. Async/Await uses JavaScript fetch API (which returns promises) for making HTTP requests.

filter-method

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Filter Method filter() method is used to create a new array with all elements that pass the test implemented by the provided function. Syntax: const newArray = array.filter(callback(element, index, array), thisArg); callback: A function that is called for every element of the array. If this function returns true, the element is included in the new array.

find-and-find-index-methods

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Find / Find Index methods Unlike filter method that returns all the matching elements, find and findIndex will stop at the first matching element found. Find The find method returns the first element in an array that satisfies a given test function. If no elements satisfy the test, it returns

for-in-vs-for-of

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

For In vs For Of The for...in and for...of loops are used to iterate over the properties of objects or elements of an iterable, but they do it in different ways. For In The for...in loop iterates over all enumerable properties of an object, including inherited ones.

function-context

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Function Context This this keyword relates to the context on which it is run. person.sayHello() => context here is person person.spouse.sayHello(); => context is spouse sayHello() => context is window for web browsers, globalThis for Node.js >=12 or

hello-world

Anonymous (anonymous@undisclosed.example.com) — 2025-01-02T18:22:18+00:00

Java Script Hello World The following script will display 'Hello World' both in a popup window and in the browser's console. To execute the script, it must be run within a web browser. HTML + JS code in the same file Hello World!

Hello World! from JS in a script tag