Function: _createDerivedProperty

function _createDerivedProperty<T, S>(
   sources,
   derive,
options?): _ReadonlyReactiveProperty<T>;

Creates a derived reactive property from one or more sources.

The value is computed from source values using a derivation function. Updates are memoized (only emit when derived value changes).

Type Parameters#

Type Parameter
`T`
`S` extends `any`[]

Parameters#

Parameter	Type	Description
`sources`	{ [K in string	number
`derive`	(…`values`) => `T`	Function that computes the derived value from source values
`options?`	`Pick`<`_ReactivePropertyOptions`<`T`>, `"equals"`>	Configuration options

Returns#

_ReadonlyReactiveProperty<T>

A read-only reactive property

Example#

const width = createReactiveProperty(800);
const height = createReactiveProperty(600);

const area = createDerivedProperty(
  [width, height],
  (w, h) => w * h
);

area.subscribe((value) => console.log('Area:', value));
width.update(1000); // Logs: "Area: 600000"