기본 타입: 숫자 + 참조(숫자 제외 타입 + 함수 객체) // undefined 형 = undefined, null 둘 다 var emptyVar; var nullVar = null; console.log(typeof emptyVar, typeof nullVar); // undefined, object console...

Let me know about Vanilla js and query methods, at least 50, make an each example and outout Vanilla JavaScript, often referred to simply as “Vanilla JS,” is just plain JavaScript without any frame...

Ah, the classic sync vs. async debate in Node.js—let’s break it down in a way that makes it easy to grasp. The difference between synchronous (sync) and asynchronous (async) comes down to how and w...

And let me know about Java and Javascript’s marks. Like ===, ==, ?, ??. Compare to each of them. Here’s a comparison of some common JavaScript operators, including strict equality (===), loose equa...

var self = function() { console.log('a'); return function () { console.log('b'); } } self()(); // a // b self = self(); // a self(); // b Let’s break this down step by step so it all makes...

Yes, cb(user)** in your code is both a Closure and a Callback Function**. Let me explain how it holds both these properties. Great question! Closures and callback functions are related concepts ...

function findUser(id) { let user; setTimeout(function () { console.log("waited 0.1 sec."); user = { id: id, name: "User" + id, email: id + "@test.com", }; }, 100...

Nope, arrow functions are not inherently asynchronous. Arrow functions are simply a shorthand syntax for writing functions in JavaScript. Whether a function is asynchronous or not depends on how it...

Tracing 목차 Tracing의 역할 Trace와 Span Context Propagation Distributed Tracing Sampling Tracing 구현 Tracing의 역할 Tracing은 하나의 사용자 요청이 여러 마이크로서비스, 데이터베이스, 캐시를 지나가며 남기는 흐름을 추적하는 관측성 기술이다...

vue-master 강의에서 다루는 내용 실습 미리보기 개발환경 node 설치 $ sudo apt update $ sudo apt install nodejs // node download $ nodejs -v // read version $ sudo apt install npm // npm(node manager) dow...