JS Built-ins
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ArrayArray.fromintermediate

Array.from() — count Unicode code points

📖 Usage Example
Array.from('hello')
// → ['h', 'e', 'l', 'l', 'o']

Use Array.from() on a string to split it into an array of individual characters.

Array.from() — Unicode-safe string splitting

str.split('') splits a string by UTF-16 code units, which breaks emoji and other characters outside the Basic Multilingual Plane into two surrogates. Array.from(str) iterates by code point, keeping emoji intact.

Challenge: Implement countCodePoints that returns the number of Unicode code points in a string using Array.from(str).length.

countCodePoints('hello')   // → 5
countCodePoints('hi 👋')   // → 4  (not 5 — emoji is one code point)
💡 Hints (2)
  • • `Array.from(str)` uses the string's Symbol.iterator which yields code points.
  • • Compare `Array.from("👋").length` (1) vs `"👋".split("").length` (2) to see the difference.