javascript – Page 26 – Türker Yıldırım

ES6 modules are not what your bundler is doing

NoteJanuary 20, 20162 min read

Writing import and export does not mean the browser is loading modules. Babel rewrites both into CommonJS, webpack resolves them at build time, and what ships is one…

Object spread is a proposal, not ES2015

NoteJanuary 7, 20161 min read

Array spread is ES2015 and object spread is not — it is a stage 3 proposal, available only through Babel, and the syntactic similarity makes it very easy…

jQuery Deferred and native Promises are not the same object

NoteDecember 22, 20151 min read

jQuery has had $.Deferred since long before the platform had promises, and it is close enough to look interchangeable. It is not: prior to 3.0 a jQuery Deferred…

querySelectorAll returns a NodeList, not an Array

NoteDecember 20, 20151 min read

A NodeList has a length and numeric indices, which is enough to make it look like an array until the first time you call map or filter on…

Arrow functions do not have their own this

NoteDecember 18, 20151 min read

The reason var self = this appears in every callback-heavy file is that a normal function gets its own this, decided by how it is called. An arrow…

Destructuring pulls values out without temporaries

NoteDecember 4, 20151 min read

Unpacking a few fields out of an options object is three or four lines of near-identical assignment at the top of every function. Destructuring does it in the…

requestAnimationFrame instead of setTimeout for animation

NoteOctober 21, 20151 min read

setTimeout(fn, 16) approximates 60fps and is wrong in both directions: it keeps firing in a background tab, burning battery on frames nobody sees, and it drifts out of…

Default parameters replace the argument-check dance

NoteAugust 20, 20151 min read

The traditional way to give a parameter a default is x = x || fallback, which is wrong whenever a legitimate value is falsy. Passing 0 for a…

Object.assign is a shallow merge, and that matters

NoteJune 19, 20151 min read

Object.assign() copies enumerable own properties from one object onto another, which reads like a deep clone and is not one. Nested objects are copied by reference, so mutating…

Copy text to the clipboard with JavaScript

SnippetJune 18, 20151 min read