Closure CavesISSUE #56 of 61

ES6 recap · let · const · arrow · class

LambdaVSThe Mutator

Lambda saysES6 (2015) was the big leap: let/const, arrow functions, classes, template literals, modules, and more.

ECMAScript 2015 (ES6) modernized JavaScript: block-scoped let/const, arrow functions, class syntax, template literals, destructuring, default/rest/spread, Map/Set, promises, and modules. Almost everything "modern JS" means started here. Since then, a new edition ships yearly with smaller, focused additions.

Power-ups you unlock

ES6/2015 = the modernization milestone
let/const, arrows, class, template literals
Destructuring, spread/rest, Map/Set, promises
Yearly editions add features since

The Mutator attacks — common mistakes

Calling everything modern "ES6" (it’s yearly now)
Avoiding features over outdated browser fears
Transpiling unnecessarily for evergreen browsers

Boss battleList which features you already use daily that arrived in ES6.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre id="o"></pre>
<script>const sq=n=>n*n; const [a,b]=[1,2]; const merged={...{x:1}};
document.getElementById('o').textContent='arrow,destructure,spread — all ES6: '+sq(a+b)+' '+JSON.stringify(merged);</script></body></html>

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