JS Built-ins
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StringString.prototype.toLocaleUpperCasebeginner

String.prototype.toLocaleUpperCase() — mixed case

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

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

String.prototype.toLocaleUpperCase() — Mixed Case

Mixed-case ASCII strings are fully uppercased.

Challenge: Implement normalizeUpper(str) that uppercases any ASCII string.

normalizeUpper('HeLLo WoRLd') // → 'HELLO WORLD'
💡 Hints (1)
  • • Every lowercase ASCII letter is converted to its uppercase equivalent.