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Components & JSX
mediumComplete guide with examples and interview questions · 40 min
Definition
Say it out loud in an interview — clear, simple, no textbook wording.
React models UI as a function of state. Components are the building blocks — each one returns a tree of elements describing what should appear on screen.
JSX is the syntax you write in .jsx files: it looks like HTML but compiles to React.createElement(type, props, ...children).
Quick Stats
40
Minutes
medium
Difficulty
4
Interview Q's
Key takeaways
- •JSX is syntactic sugar for React.createElement
- •Components are functions that return UI descriptions
- •Props flow down; each render produces a new element tree
- •Reconciliation compares element type and keys on updates
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