number static method

String? number(String? value, { double? min, double? max, })

Validates that the input is a number.

Implementation

static String? number(String? value, {double? min, double? max}) {
  if (value == null || value.trim().isEmpty) return 'This field is required';

  final number = double.tryParse(value);
  if (number == null) return 'Invalid number';

  if (min != null && number < min) {
    return 'Number must be at least $min';
  }

  if (max != null && number > max) {
    return 'Number must be at most $max';
  }

  return null;
}