integer static method

String? integer(
  1. String? value, {
  2. String message = "Enter valid integer",
})

Implementation

static String? integer(String? value, {String message = "Enter valid integer"}) {
  if (value == null || value.isEmpty) return null;

  if (int.tryParse(value) == null) {
    return message;
  }
  return null;
}