JS Built-ins
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StringString.prototype.toLocaleUpperCasebeginner

String.prototype.toLocaleUpperCase() — basic ASCII uppercase

📖 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()

str.toLocaleUpperCase() converts a string to uppercase using the host locale's rules. For ASCII strings, the result is deterministic.

Challenge: Implement localeUpper(str) that converts the string to uppercase.

localeUpper('hello') // → 'HELLO'
💡 Hints (1)
  • • For ASCII strings, `toLocaleUpperCase()` behaves identically to `toUpperCase()`.