Benchmark: Object.create(null) vs Object literal - Creation and Iteration Performance (including Object.keys vs hasOwnPropertyCheck)

Tests:

Object.create
const object = Object.create(null); object.a = 1; object.b = 2; object.c = 3; object.d = 4; object.e = 5; object.f = 6; object.g = 7; object.h = 8; let sum = 0, key; for (key in object) { sum += object[key]; }
Object literal (hasOwnProperty check iteration)
const object = {a: 1, b: 2, c: 3, d: 4, e: 5, f: 6, f: 7, h: 8}; let sum = 0, key; for (key in object) { if (object.hasOwnProperty(key)) { sum += object[key]; } }
Object literal (keys() iteration)
const object = {a: 1, b: 2, c: 3, d: 4, e: 5, f: 6, f: 7, h: 8}; const keys = Object.keys(object); let sum = 0; for (let i = 0, key; i < keys.length; i++) { sum += object[keys[i]]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.create
Object literal (hasOwnProperty check iteration)
Object literal (keys() iteration)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:129.0) Gecko/20100101 Firefox/129.0

Browser/OS: Firefox 129 on Windows

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Object literal (hasOwnProperty check iteration)

12.5M/s

Object.create

12.2M/s

Object literal (keys() iteration)

10.5M/s

View exact numbers

Test name	Executions per second
✓ Object literal (hasOwnProperty check iteration)	12,477,613 Ops/sec
Object.create	12,176,886 Ops/sec
Object literal (keys() iteration)	10,485,983 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

The provided JSON represents a benchmark test case on MeasureThat.net, which compares the performance of two different ways to create and iterate over objects in JavaScript:

1. Using `Object.create(null)` and iterating with a simple `for...in` loop.
2. Creating an object literal (`{a: 1, b: 2, ...}`) and iterating with either a simple `for...in` loop with a `hasOwnProperty()` check or using the `Object.keys()` method.

**Test Case 1: Object.create(null)**

This test case creates an object using `Object.create(null)` and then sets properties on it (`object.a = 1;`, etc.). The iteration is done using a simple `for...in` loop:
```javascript
let sum = 0, key;
for (key in object) {
  sum += object[key];
}
```
This approach creates an object with no prototype chain, which can be beneficial for certain use cases.

**Test Case 2: Object literal (hasOwnProperty check iteration)**

In this test case, an object is created using the object literal syntax (`{a: 1, b: 2, ...}`). The iteration is done using a `for...in` loop with a `hasOwnProperty()` check:
```javascript
let sum = 0, key;
for (key in object) {
  if (object.hasOwnProperty(key)) {
    sum += object[key];
  }
}
```
This approach creates an object with the default prototype chain. The `hasOwnProperty()` check is used to ensure that only own properties are iterated over.

**Test Case 3: Object literal (keys() iteration)**

In this test case, an object is created using the object literal syntax (`{a: 1, b: 2, ...}`). The iteration is done using `Object.keys()` method followed by a simple `for` loop:
```javascript
const keys = Object.keys(object);
let sum = 0;
for (let i = 0, key; i < keys.length; i++) {
  sum += object[keys[i]];
}
```
This approach also creates an object with the default prototype chain. The `Object.keys()` method returns an array of own property names, which is then iterated over.

**Pros and Cons**

The pros and cons of each approach are:

* **Object.create(null)**:
	+ Pros: Creates an object with no prototype chain, can be beneficial for certain use cases (e.g., when you need to avoid inheritance).
	- Cons: May not work as expected if used in conjunction with other features that rely on the default prototype chain.
* **Object literal (hasOwnProperty check iteration)**:
	+ Pros: Creates an object with the default prototype chain, which is what most developers expect. The `hasOwnProperty()` check ensures only own properties are iterated over.
	- Cons: May have performance implications due to the overhead of the `hasOwnProperty()` method call for each property.
* **Object literal (keys() iteration)**:
	+ Pros: Creates an object with the default prototype chain, and uses a more efficient approach than the `hasOwnProperty()` check iteration. The `Object.keys()` method returns an array, which can be iterated over using a simple `for` loop.
	- Cons: May have performance implications due to the overhead of creating an array of property names.

**Other Alternatives**

There are other ways to create and iterate over objects in JavaScript:

* **Using `Object.assign()`**: This method creates a new object by merging one or more source objects with an existing object. Iteration can be done using a simple `for...in` loop.
* **Using a library like Lodash**: The `_`.keys() method returns an array of own property names, which can be iterated over using a simple `for` loop.

Keep in mind that the performance implications and pros/cons of each approach may vary depending on the specific use case and requirements.

Object.create(null) vs Object literal - Creation and Iteration Performance (including Object.keys vs hasOwnPropertyCheck) (version: 0) Benchmark.js

Comparing performance of: `Object.create vs Object literal (hasOwnProperty check iteration) vs Object literal (keys() iteration)`

Created: 4 years ago by: Guest

Go to the latest result

Object.create

Object literal (hasOwnProperty check iteration)

Object literal (keys() iteration)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

Object.create(null) vs Object literal - Creation and Iteration Performance (including Object.keys vs hasOwnPropertyCheck) (version: 0) Benchmark.js

Comparing performance of: Object.create vs Object literal (hasOwnProperty check iteration) vs Object literal (keys() iteration)

Created: 4 years ago by: Guest

Go to the latest result

Object.create

Object literal (hasOwnProperty check iteration)

Object literal (keys() iteration)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

Related benchmarks

Comparing performance of: `Object.create vs Object literal (hasOwnProperty check iteration) vs Object literal (keys() iteration)`