JS Built-ins
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StringString.prototype.toLocaleLowerCasebeginner

String.prototype.toLocaleLowerCase() — mixed case

📖 Usage Example
'HELLO'.toLocaleLowerCase()   // → 'hello'
'WORLD'.toLocaleLowerCase()   // → 'world'
'ABC123'.toLocaleLowerCase()  // → 'abc123'

Use toLocaleLowerCase() to convert a string to lowercase using the locale-specific rules of the host environment.

String.prototype.toLocaleLowerCase() — Mixed Case

Mixed-case ASCII strings are fully lowercased.

Challenge: Implement normalizeLower(str) that lowercases any ASCII string.

normalizeLower('HeLLo WoRLd') // → 'hello world'
💡 Hints (1)
  • • Every uppercase ASCII letter is converted to its lowercase equivalent.