l.double()

Passes when the value is double. Returns a DoubleValidator with .min(), .max() and .finite(). On the VM an int such as 42 fails, and jsonDecode produces an int for 42, so a JSON field that may arrive without a decimal point should use l.num(). NaN and infinity are doubles and pass until you add .finite().

Signature

NumberValidator<double, double?> double({String? message, MessageBuilder? messageBuilder})

Parameters

Parameter	Type	Meaning
message	String?	Replaces the default error message.
messageBuilder	MessageBuilder?	Builds the message from the issue. message wins when both are given. See Message builders.

Issue

Code invalidType. Default message: value must be a double. value is replaced by the field name when there is one.

Code generation

A double parameter maps to l.double(), which rejects JSON integers. That is deliberate: the validator mirrors the Dart type. If your backend may send 1 for a double field, type the field as num. @HasMin(n) and @HasMax(n) add .min(n) and .max(n).

Example

Hand-written

final ratio = l.double();

Generated

@HasMin(0) required double price, // l.double().min(0).required()
required num total,                // l.num().required(), accepts 1 and 1.0

ratio.validate(input)+2-1

1. +valid: 0.75
2. -invalid: 42value must be a double
3. +valid: double.nan