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Area final ​

final class Area extends Quantity<Area>

A quantity representing a two-dimensional area.

Inheritance

Object → Quantity<A extends Quantity<A>> → Area

Constructors ​

Area() ​

Area(double value, UnitOfMeasure<Area> unit)
Implementation
dart
Area(super.value, super.unit);

Properties ​

hashCode no setter inherited ​

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Inherited from Quantity.

Implementation
dart
@override
int get hashCode => Object.hash(value, unit);

runtimeType no setter inherited ​

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation
dart
external Type get runtimeType;

toAcres no setter ​

Area get toAcres

Converts this to acres.

Implementation
dart
Area get toAcres => to(acres).acres;

toBarnes no setter ​

Area get toBarnes

Converts this to barns (b), used in nuclear physics.

Implementation
dart
Area get toBarnes => to(barnes).barnes;

toHectares no setter ​

Area get toHectares

Converts this to hectares (ha).

Implementation
dart
Area get toHectares => to(hectares).hectares;

toSquareCentimeters no setter ​

Area get toSquareCentimeters

Converts this to square centimeters (cm²).

Implementation
dart
Area get toSquareCentimeters => to(squareCentimeters).squareCentimeters;

toSquareFeet no setter ​

Area get toSquareFeet

Converts this to square feet (ft²).

Implementation
dart
Area get toSquareFeet => to(squareFeet).squareFeet;

toSquareInches no setter ​

Area get toSquareInches

Converts this to square inches (in²).

Implementation
dart
Area get toSquareInches => to(squareInches).squareInches;

toSquareKilometers no setter ​

Area get toSquareKilometers

Converts this to square kilometers (km²).

Implementation
dart
Area get toSquareKilometers => to(squareKilometers).squareKilometers;

toSquareMeters no setter ​

Area get toSquareMeters

Converts this to square meters (m²).

Implementation
dart
Area get toSquareMeters => to(squareMeters).squareMeters;

toSquareUsMiles no setter ​

Area get toSquareUsMiles

Converts this to square US miles (mi²).

Implementation
dart
Area get toSquareUsMiles => to(squareUsMiles).squareUsMiles;

toSquareYards no setter ​

Area get toSquareYards

Converts this to square yards (yd²).

Implementation
dart
Area get toSquareYards => to(squareYards).squareYards;

unit final inherited ​

final UnitOfMeasure<Area> unit

The unit of measure that value is expressed in.

Inherited from Quantity.

Implementation
dart
final UnitOfMeasure<A> unit;

value final inherited ​

final double value

The raw numeric value of this quantity expressed in unit.

Inherited from Quantity.

Implementation
dart
final double value;

Methods ​

equivalentTo() inherited ​

bool equivalentTo(Quantity<Area> other)

Returns true if this quantity represents the same physical magnitude as other, regardless of which unit each is expressed in.

Inherited from Quantity.

Implementation
dart
bool equivalentTo(Quantity<A> other) => other.to(unit) == value;

noSuchMethod() inherited ​

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dart
dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

dart
class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation
dart
@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

to() inherited ​

double to(UnitOfMeasure<Area> uom)

Converts this quantity to uom and returns the raw double value.

If uom equals unit, the current value is returned unchanged.

Inherited from Quantity.

Implementation
dart
double to(UnitOfMeasure<A> uom) => uom == unit ? value : uom.convertTo(unit.convertFrom(value));

toString() inherited ​

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Quantity.

Implementation
dart
@override
String toString() => '$value ${unit.symbol}';

Operators ​

operator *() ​

Volume operator *(Length that)

Multiplies this area by that length to produce a Volume.

The result unit is chosen to match the unit of this where possible (e.g. squareFeet * feet → cubicFeet); otherwise defaults to cubic meters.

Implementation
dart
Volume operator *(Length that) => switch (unit) {
  SquareUsMiles _ => Volume.cubicUsMiles(value * that.toUsMiles.value),
  SquareYards _ => Volume.cubicYards(value * that.toYards.value),
  SquareFeet _ => Volume.cubicFeet(value * that.toFeet.value),
  SquareInches _ => Volume.cubicInches(value * that.toInches.value),
  _ => Volume.cubicMeters(toSquareMeters.value * that.toMeters.value),
};

operator +() ​

Area operator +(Area that)

Returns the sum of this and that in the units of this Area.

Implementation
dart
Area operator +(Area that) => Area(value + that.to(unit), unit);

operator -() ​

Area operator -(Area that)

Returns the difference between this and that in the units of this Area.

Implementation
dart
Area operator -(Area that) => Area(value - that.to(unit), unit);

operator /() ​

Length operator /(Length that)

Divides this area by that length to produce a Length.

The result unit is chosen to match the unit of this where possible; otherwise defaults to meters.

Implementation
dart
Length operator &#47;(Length that) => switch (unit) {
  SquareUsMiles _ => Length.usMiles(value &#47; that.toUsMiles.value),
  SquareYards _ => Length.yards(value &#47; that.toYards.value),
  SquareFeet _ => Length.feet(value &#47; that.toFeet.value),
  SquareInches _ => Length.inches(value &#47; that.toInches.value),
  _ => Length.meters(toSquareMeters.value &#47; that.toMeters.value),
};

operator <() inherited ​

bool operator <(Area that)

Returns true if this quantity is less than that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation
dart
bool operator <(A that) => value < that.to(unit);

operator <=() inherited ​

bool operator <=(Area that)

Returns true if this quantity is less than or equal to that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation
dart
bool operator <=(A that) => value <= that.to(unit);

operator ==() inherited ​

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

  • Total: It must return a boolean for all arguments. It should never throw.

  • Reflexive: For all objects o, o == o must be true.

  • Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

  • Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from Quantity.

Implementation
dart
@override
bool operator ==(Object other) =>
    identical(this, other) ||
    (other is Quantity<A> && other.value == value && other.unit == unit);

operator >() inherited ​

bool operator >(Area that)

Returns true if this quantity is greater than that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation
dart
bool operator >(A that) => value > that.to(unit);

operator >=() inherited ​

bool operator >=(Area that)

Returns true if this quantity is greater than or equal to that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation
dart
bool operator >=(A that) => value >= that.to(unit);

Static Methods ​

parse() override ​

Option<Area> parse(String s)

Parses s into an Area, returning None if parsing fails.

Implementation
dart
static Option<Area> parse(String s) => Quantity.parse(s, units);

Constants ​

acres ​

const AreaUnit acres

Unit for acres.

Implementation
dart
static const AreaUnit acres = Acres._();

barnes ​

const AreaUnit barnes

Unit for barns (b) — 10⁻²⁸ m², used in nuclear and particle physics.

Implementation
dart
static const AreaUnit barnes = Barnes._();

hectares ​

const AreaUnit hectares

Unit for hectares (ha).

Implementation
dart
static const AreaUnit hectares = Hectares._();

squareCentimeters ​

const AreaUnit squareCentimeters

Unit for square centimeters (cm²).

Implementation
dart
static const AreaUnit squareCentimeters = SquareCentimeters._();

squareFeet ​

const AreaUnit squareFeet

Unit for square feet (ft²).

Implementation
dart
static const AreaUnit squareFeet = SquareFeet._();

squareInches ​

const AreaUnit squareInches

Unit for square inches (in²).

Implementation
dart
static const AreaUnit squareInches = SquareInches._();

squareKilometers ​

const AreaUnit squareKilometers

Unit for square kilometers (km²).

Implementation
dart
static const AreaUnit squareKilometers = SquareKilometers._();

squareMeters ​

const AreaUnit squareMeters

Unit for square meters (m²).

Implementation
dart
static const AreaUnit squareMeters = SquareMeters._();

squareUsMiles ​

const AreaUnit squareUsMiles

Unit for square US miles (mi²).

Implementation
dart
static const AreaUnit squareUsMiles = SquareUsMiles._();

squareYards ​

const AreaUnit squareYards

Unit for square yards (yd²).

Implementation
dart
static const AreaUnit squareYards = SquareYards._();

units ​

const Set<AreaUnit> units

All supported Area units.

Implementation
dart
static const units = {
  squareMeters,
  squareCentimeters,
  squareKilometers,
  squareUsMiles,
  squareYards,
  squareFeet,
  squareInches,
  hectares,
  acres,
  barnes,
};