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Segments (max 10)

  • 00:00 – 05:00🎬 Intro & roadmap

    Neutral

    Who’s talking: Host

    • Intro and roadmap for the 100 concepts format.
    • Primitives, typeof quirks, and BigInt note.

  • 05:00 – 15:00🧱 Scope & closures

    Educational

    Who’s talking: Host

    • Scope: function vs block; TDZ for let/const.
    • Closures with a tiny counter example.

  • 15:00 – 30:00⚡ this, arrows, classes

    Comedy

    Who’s talking: Host

    • this binding rules; arrow functions vs regular.
    • Prototypes, classes as sugar, extends behavior.

  • 30:00 – 45:00

    Neutral

    Who’s talking: not identified

    • Promises, async/await, error handling patterns.
    • Event loop: microtasks vs macrotasks.
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100 JavaScript concepts you need to know

Fast tour of core JS ideas from closures to event loop—good refresher before interviews.

Fireship · 8:42 · Nov 15, 2025 · Click a segment to jump in the player

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Description preview

Welcome back to the channel. Today we are blasting through one hundred JavaScript concepts you should know. We will cover primitives, coercion, closures, prototypes, async patterns, and the event loop. Grab a coffee—this will move fast. First up: let versus const versus var, and why block scope matters in modern codebases…

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