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This is available as Str\starts_with_ci_l in the www repository.

Returns whether the string starts with the given prefix (case-insensitive)

namespace HH\Lib\Str;

function starts_with_ci_l(
  \HH\Lib\Locale\Locale $locale,
  string $string,
  string $prefix,
): bool;

Locale-specific collation rules will be followed, and strings will be normalized in encodings that support multiple representations of the same characters, such as UTF8.

For a case-sensitive check, see Str\starts_with().


  • \HH\Lib\Locale\Locale $locale
  • string $string
  • string $prefix


  • bool