Benchmark: Object look-up - MeasureThat.net

Script Preparation code:

var withPrototype = {};
var withoutPrototype = Object.create(null);

for (var i=0; i<100; ++i) {
  withPrototype[i] = true;
  withoutPrototype[i] = true;
}

var hasOwnProperty = Object.prototype.hasOwnProperty;

Tests:

access property with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (withPrototype[key]) continue; }
access property without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (withoutPrototype[key]) continue; }
in with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (key in withPrototype) continue; }
in without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (key in withoutPrototype) continue; }
hasOwnProperty with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (hasOwnProperty.call(withPrototype, key)) continue; }
hasOwnProperty without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (hasOwnProperty.call(withoutPrototype, key)) continue; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
access property with prototype
access property without prototype
in with prototype
in without prototype
hasOwnProperty with prototype
hasOwnProperty without prototype

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The benchmark measures the performance of different approaches to accessing properties in JavaScript objects, specifically:

1. `in` operator
2. Property access with prototype chain (`withPrototype[key]`)
3. `hasOwnProperty.call()` method

The benchmark consists of six test cases, each with a unique setup and comparison.

**Test Cases**

1. **Access property with prototype**: This test case compares the performance of accessing properties using the dot notation (`withPrototype[i]`) versus the `in` operator (`key in withPrototype`).
	* Pros: Easy to understand and implement.
	* Cons: May be slower due to the additional overhead of resolving the prototype chain.
2. **Access property without prototype**: This test case compares the performance of accessing properties using the dot notation (`withoutPrototype[i]`) versus the `in` operator (`key in withoutPrototype`).
	* Pros: Similar to test 1, but with a more direct path to the property.
	* Cons: May be slower due to the absence of the prototype chain.
3. **In with prototype**: This test case compares the performance of using the `in` operator (`key in withPrototype`) versus accessing properties directly using the dot notation (`withPrototype[key]`).
	* Pros: Faster than test 1, as it avoids the overhead of resolving the prototype chain.
	* Cons: May not be as readable or intuitive as test 1.
4. **In without prototype**: This test case compares the performance of using the `in` operator (`key in withoutPrototype`) versus accessing properties directly using the dot notation (`withoutPrototype[key]`).
	* Pros: Similar to test 3, but with a more direct path to the property.
	* Cons: May be slower due to the absence of the prototype chain.
5. **HasOwnProperty with prototype**: This test case compares the performance of using `hasOwnProperty.call()` method (`hasOwnProperty.call(withPrototype, key)`) versus accessing properties directly using the dot notation (`withPrototype[key]`).
	* Pros: Faster than test 1, as it avoids the overhead of resolving the prototype chain.
	* Cons: May not be as readable or intuitive as test 1.
6. **HasOwnProperty without prototype**: This test case compares the performance of using `hasOwnProperty.call()` method (`hasOwnProperty.call(withoutPrototype, key)`) versus accessing properties directly using the dot notation (`withoutPrototype[key]`).
	* Pros: Similar to test 5, but with a more direct path to the property.
	* Cons: May be slower due to the absence of the prototype chain.

**Library and Special Features**

The benchmark uses the `Object.create()` method to create objects without a prototype chain (`withoutPrototype`). This is an ECMAScript feature that allows creating objects without a prototype chain, which can affect performance.

There are no special JavaScript features or syntax used in this benchmark beyond what's required for testing. However, the use of `Object.prototype.hasOwnProperty` in some test cases implies the use of the `hasOwnProperty` method, which is a part of the ECMAScript standard.

**Other Alternatives**

Alternative approaches to accessing properties in JavaScript could include:

1. Using a more modern approach like using `Map` or `WeakMap` instead of objects.
2. Employing a caching mechanism to store frequently accessed properties.
3. Utilizing specialized libraries or frameworks that optimize property access, such as `fast-args` or `js-fast`.
4. Implementing a custom optimization technique specific to the use case.

Keep in mind that these alternatives may not provide significant performance benefits for all scenarios and might introduce additional complexity or dependencies.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0

Browser/OS: Firefox 57 on Windows 7

View result in a separate tab

Test name	Executions per second
access property with prototype	1360200.4 Ops/sec
access property without prototype	1359542.9 Ops/sec
in with prototype	1444515.1 Ops/sec
in without prototype	1385172.9 Ops/sec
hasOwnProperty with prototype	1033283.2 Ops/sec
hasOwnProperty without prototype	1016808.5 Ops/sec

Related benchmarks:

Object look-up (version: 0)

Comparing performance of: access property with prototype vs access property without prototype vs in with prototype vs in without prototype vs hasOwnProperty with prototype vs hasOwnProperty without prototype

Created: 7 years ago by: Guest

Jump to the latest result

access property with prototype

access property without prototype

in with prototype

in without prototype

hasOwnProperty with prototype

hasOwnProperty without prototype

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):