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Define Memoized Property

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Define a memoized object property.


npm install @stdlib/utils-define-memoized-property


var defineMemoizedProperty = require( '@stdlib/utils-define-memoized-property' );

defineMemoizedProperty( obj, prop, descriptor )

Defines a memoized object property.

var obj = {};

function foo() {
    return 'bar';

defineMemoizedProperty( obj, 'foo', {
    'configurable': false,
    'enumerable': true,
    'writable': false,
    'value': foo

var v = obj.foo;
// returns 'bar'

A property descriptor has the following required properties:

  • value: synchronous function whose return value will be memoized and set as the property value.

A property descriptor has the following optional properties:

  • configurable: boolean indicating if property descriptor can be changed and if the property can be deleted from the provided object. Default: false.
  • enumerable: boolean indicating if the property shows up when enumerating object properties. Default: false.
  • writable: boolean indicating if the value associated with the property can be changed with an assignment operator. Default: false.


  • Until deferred evaluation, an object property is configurable.


var fibonacci = require( '@stdlib/math-base-special-fibonacci' );
var defineMemoizedProperty = require( '@stdlib/utils-define-memoized-property' );

function Foo() {
    var self;
    if ( !(this instanceof Foo) ) {
        return new Foo();
    self = this;
    this.count = 0;
    defineMemoizedProperty( this, 'fibo', {
        'value': fibo
    return this;

    function fibo() {
        self.count += 1;
        return fibonacci( 73 );

var foo = new Foo();

var i;
for ( i = 0; i < 10; i++ ) {
    console.log( 'F: %d. Count: %d.', foo.fibo, foo.count );

See Also


This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.






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  • stdlib-bot
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