isDigit function

bool isDigit(
  1. String char
)

Checks whether the given string is a single digit from 0 to 9.

Implementation

bool isDigit(final String char) {
  if (char.length != 1) {
    return false;
  }
  final int code = char.codeUnitAt(0);
  return code >= _digit0 && code <= _digit9;
}