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JavaScript Core Concepts
Closures, hoisting, event loop, promises
15 min read+200 XP on completionCert: Frontend Engineering
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# JavaScript Core Concepts
Closures
A function that retains access to its outer scope after the outer function returns.
Hoisting
var and function declarations are hoisted. let and const are in the temporal dead zone until declared.
Event Loop
Call stack runs synchronous code. Microtask queue (Promises) drains next. Macrotask queue (setTimeout) runs after.
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Closure
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