ML SystemPart 2: Chapter 6
CH.06 ~25 min
Async JS
Event Loop, Promises, and Axios.
Event LoopPromisesAxios
- Explain the mechanics of the JavaScript Event Loop.
- Fetch data from a remote API using Axios and Promises.
- Integrate network requests into React components using useEffect.
01 Asynchronous Execution & Event Loop Viz
Definition
Event Loop
A mechanism that allows JavaScript to perform non-blocking I/O operations by delegating heavy tasks to the browser's Web APIs.
Single-Threaded but ResponsiveDeeper InsightWhile the engine executes one task at a time, it delegates network requests to the system, picking up the results only when they are ready. Click to collapse
02 Promises & Axios
- **Pending**: The network request is in progress.
- **Fulfilled**: The request succeeded (HTTP 2xx).
- **Rejected**: The request failed (HTTP 4xx/5xx).
useEffect for Side Effects
Data fetching is a side effect. In React, we use the useEffect hook with an empty dependency array to fetch data once when the component mounts.
Key Takeaways
- 1JavaScript's Event Loop enables non-blocking asynchronous operations.
- 2Promises have three states: Pending, Fulfilled, and Rejected.
- 3useEffect is the standard place to trigger API calls in React components.
CH.06
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Exercise
Interact with the visualization
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