isDigit

Selects ASCII digits, i.e. '0'..'9'.
A fast digit predicate.
Decimal digit predicate.
Decimal digit predicate.
A fast digit predicate.
Test if a character is a digit.
Determines whether a character is numeric (i.e. a digit). This covers ASCII 0-9 and also digits in other languages/scripts. Given some UTF-8 text, obtain a character value with utf8GetChar.