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LetsGit.IT/Categories/JavaScript
JavaScriptmedium

What is type coercion? Give a surprising example.

Tags
#coercion#types
Back to categoryPractice quiz

Answer

Type coercion is automatic conversion between types (e.g., 3 + 2 + "7" becomes "57").

Advanced answer

Deep dive

Expanding on the short answer — what usually matters in practice:

  • Context (tags): coercion, types
  • Explain the "why", not just the "what" (intuition + consequences).
  • Trade-offs: what you gain/lose (time, memory, complexity, risk).
  • Edge cases: empty inputs, large inputs, invalid inputs, concurrency.

Examples

A tiny example (an explanation template):

// Example: discuss trade-offs for "what-is-type-coercion?-give-a-surprising-example"
function explain() {
  // Start from the core idea:
  // Type coercion is automatic conversion between types (e.g., 3 + 2 + "7" becomes "57").
}

Common pitfalls

  • Too generic: no concrete trade-offs or examples.
  • Mixing average-case and worst-case (e.g., complexity).
  • Ignoring constraints: memory, concurrency, network/disk costs.

Interview follow-ups

  • When would you choose an alternative and why?
  • What production issues show up and how do you diagnose them?
  • How would you test edge cases?

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