the murmurous sea

https://medium.com/better-programming/should-i-use-promises-or-async-await-126ab5c98789#:~:text=Promise%20creation%20starts%20the%20execution,have%20any%20effect%20on%20it. JavaScript: Promises or async-await A set of rules for when to use which medium.com https://medium.com/better-programming/understanding-promises-in-javascript-13d99df067c1 Understanding Promises in JavaScript An in-depth look..

"JavaScript는 객체(인스턴스)와 객체 간의 상속 관계를 자유롭게 설정할 수 있습니다." from https://opentutorials.org/module/4047/24626 객체 간의 상속 - JavaScript 객체 지향 프로그래밍 수업소개 JavaScript는 객체(인스턴스)와 객체 간의 상속 관계를 자유롭게 설정할 수 있습니다. 이 수업에서는 클래스가 아닌 객체를 통해서 상속하는 방법을 알아봅니다. 강의1 자바스크립트의 � opentutorials.org instance : An “instance” means a reference to an “object” created by “new” or the equivalent. from https://www.quora.com/What-is-an-..

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode Strict mode JavaScript's strict mode, introduced in ECMAScript 5, is a way to opt in to a restricted variant of JavaScript, thereby implicitly opting-out of "sloppy mode". Strict mode isn't just a subset: it intentionally has different semantics from normal code. Brow developer.mozilla.org https://m.blog.naver.com/on21..

class Person { constructor (name, first, second) { this.name = name; this.first = first; this.second = second; } } const Kim = new Person(Kim, 10, 20); console.log('Kim:', Kim); 위의 코드처럼 const나 let을 사용하면 temporal dead zone에 있게 되어 코드를 실행할 수 없음 class와 const/let 모두 ES6에서 새로 추가된 기능인데, 왜 같이 사용할 수 없지...? 어떻게 해야 같이 사용할 수 있지?

1. method 2. creates a new, shallow-copied Array instance from an array-like or iterable object. 3. The length property of the from() method is 1. 4. In ES2015, the class syntax allows sub-classing of both built-in and user-defined classes. : As a result, static methods such as Array.from() are "inherited" by subclasses of Array, and create new instances of the subclass, not Array. [Syntax] Arra..

검색어를 칠 때 버튼을 누르고 난 직후에 검색이 되게 하려고 함 keydown은 검색어를 입력한 직후는 앞에 값을 보여줌. 그 다음 문자를 넣어야 전에 입력한 것이 출력됨. keyup은 누름과 동시에 값이 출력됨 왜 그렇지....?? >> because of the firing moment. The key value adds later when I use keydown in the event listener. Because the default comes later than key event. keydown keypress keyup This event has been deprecated, no longer recommended. Use beforeinput or keydown instead. firin..

The study started from: I can't hoist const function...?! Why...? A. Declaring Variables www.youtube.com/watch?v=dzEieWaOJE0&t=5s www.youtube.com/watch?v=j-9_15QBW2s B. Temporal Dead Zone It's because of : Unlike variables declared with var, which will start with the value undefined, let variables are not initialized until their definition is evaluated. : Accessing the variable before the initia..

What is Event? - The Event interface represents an event which takes place in the DOM. - An event can be triggered by the user action or can also be triggered programmatically. - Event itself contains the properties and methods which are common to all events. - 이벤트는 이벤트 대상, 이벤트 종류, 이벤트가 발생했을 때 실행되는 함수, 이 3가지로 구성 Constructor Event() How to add 1. HTML tag - inline: add the function to the tag pro..

https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener

About null. https://developer.mozilla.org/en-US/docs/Glossary/Primitive Primitive In JavaScript, a primitive (primitive value, primitive data type) is data that is not an object and has no methods. There are 6 primitive data types: string, number, bigint, boolean, undefined, and symbol. There also is null, which is seemingly primitive developer.mozilla.org "There also is null, which is seemingly..