Skip to main content
SimilarExport ZIP
100%

JS Class __proto__ Proxy

✓ Published0🌍 Public
NN0taN3rd
Last edited Jul 24, 2017
Created on Jul 24, 2017

This example demonstrates a JavaScript class that uses a Proxy to create a counter with automatic default values and type enforcement. The `Counter` class wraps a plain object in a `Proxy`, intercepting `get` operations to initialize missing keys to zero and `set` operations to reject non-numeric values. It provides iterator methods like `entries`, `sortedEntries`, and `sorted` for retrieving and ordering the counted data, using standard JavaScript iterators and `Object.entries`. The code relies solely on native JavaScript APIs, including the `Proxy` traps `get`, `set`, `has`, `ownKeys`, and `getOwnPropertyDescriptor`.

AI-generated description

Similar vizzes

Loading thumbnail…

Prototype Chains

Prototype Chains demonstrates JavaScript’s prototype-based inheritance through a series of code excerpts. It shows property lookup behavior, including failed lookups returning `undefined`, and contrasts one-time copying with `extend()` against ongoing delegation using `Object.create()`. The example illustrates how a linked object (rose) delegates missing property lookups to its prototype (gold), while copied objects (blue) do not reflect later additions. It also introduces the object prototype, the top-level fallback providing shared methods like `toString` for all objects.

MMurithi
53% match
Loading thumbnail…

An approach to deep cloning objects in JavaScript

This example shows a recursive approach to deep cloning plain JavaScript objects, where each nested object is duplicated rather than shared by reference. The code defines a `cloneDeep` function that iterates over an object’s own enumerable properties using `Object.entries`, checks whether each value is an object with `typeof value === 'object'`, and if so, calls itself recursively; otherwise, it assigns the primitive value directly. The visualization likely demonstrates this process step by step, perhaps animating the traversal of a sample object tree. However, the code explicitly notes it does not support arrays, converting them into object-like structures with numeric keys, as seen in the comment about `['foo', 'bar']` becoming `{0: 'foo', 1: 'bar'}`. No external libraries are used—only native JavaScript methods and operators.

115Dkatz
51% match
Loading thumbnail…

JS Bin

This example demonstrates a live counter that updates every second, displaying the number of elapsed seconds in the browser and the console. It uses RxJS’s `Observable.timer` to emit sequential integers, which are mapped to formatted strings. The resulting data stream is subscribed to by two effects: a DOM effect that writes the text into a `#app` container, and a console effect that logs each message. The code separates the main data stream from its side effects, following a simple functional reactive programming pattern.

JJaxonDvl
51% match
Loading thumbnail…

Classes

This example shows how JavaScript classes can be constructed using three different patterns: functional, prototypal, and pseudoclassical. It uses plain JavaScript functions, the `Object.create` API, and the `new` keyword to demonstrate object creation and method delegation through the `Car.prototype` object. The code defines a `Car` class with a `move` method that increments a `loc` property, illustrating how each pattern achieves the same behavior with varying levels of syntactic convenience.

MMurithi
50% match
Loading thumbnail…

Hidden classes in JavaScript and Inline Caching

This example illustrates how the V8 JavaScript engine optimizes object property access through hidden classes and inline caching, using a Person constructor with `firstName` and `lastName` properties. The visualization shows the creation of hidden classes (C0, C1, C2) as objects are initialized, and demonstrates how adding an `age` property changes the class chain. It also depicts assembly-level code snippets showing how V8 replaces a call to the Inline Cache with a direct memory address for a ~20x speed improvement, and explains when deoptimizations occur. The source is a Markdown document from a gist by Jastor11.

JJastor11
50% match
Loading thumbnail…

Trying to learn to use objects created in JS

This example demonstrates JavaScript object-oriented programming using a custom `ToDo` constructor and prototype methods. The code defines a `ToDo` function that assigns an `action` property, then extends it with a `sayAction` method via the prototype. Two instances, `grace` and `mistyblunch`, are created and their `sayAction` methods are called, logging their respective action strings to the console. The script also directly accesses and logs the `action` properties of each object. It uses no external libraries or data sources, relying solely on native JavaScript object creation, constructor functions, and prototype-based inheritance to illustrate basic object behavior and property access.

MMistyBlunch
48% match
Loading thumbnail…

JavaScript Arrays

This example demonstrates how JavaScript’s built-in array methods can transform and organize data, specifically by sorting an array of objects by their `key` property. It shows the result of calling `entries.sort((a,b) => a.key < b.key ? -1:1)`, which arranges the entries alphabetically by key. The code also includes commented-out examples of `filter`, `map`, `reduce`, and numeric sorting with comparator functions, illustrating pitfalls like lexicographic sorting of numbers. The implementation relies solely on native JavaScript array APIs, with no external libraries or rendering, outputting results to the console.

Kkwambokar
48% match
Loading thumbnail…

JS Arrays

This example demonstrates JavaScript array manipulation using a custom `range` function to generate an array of ten numbers, then mapping each element to an object containing the original number and its double. The code logs the resulting array of objects to the browser console. It uses the native array methods `push`, `map`, and `forEach`, with additional commented-out examples showing `filter`, `sort`, and `reverse` operations. The visualization is purely text-based, with output appearing in the developer console rather than on the page.

Bbei2
48% match