Benchmark: Object vs Object.seal

Script Preparation code:

var normal = {
  x: 1,
  y: 2,
  z: 0
};
var seal = Object.seal({
  x: 1,
  y: 2,
  z: 0
});
var tmp = {
  x: 0,
  y: 0,
  z: 0
};
var k;
var v;

Tests:

normal
normal.z = normal.x + normal.y; for (k in normal) { tmp[k] = normal[k]; } for ([k, v] of Object.entries(normal)) { tmp[k] = v; }
seal
seal.z = seal.x + seal.y; for (k in seal) { tmp[k] = seal[k]; } for ([k, v] of Object.entries(seal)) { tmp[k] = v; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
normal
seal

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Linux

View result in a separate tab

Test name	Executions per second
normal	732570.4 Ops/sec
seal	737294.8 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what is being tested.

**Benchmark Overview**

The benchmark compares the performance of two JavaScript objects: a normal object and an Object.seal()-created object. The goal is to determine which approach is faster for certain operations.

**Object vs Object.seal**

In JavaScript, an object can be modified in several ways:

1. **Normal Object**: An object is a basic data structure that can be created using the `{}` syntax. Objects are mutable, meaning their properties can be added or removed at runtime.
2. **Object.seal()**: The `Object.seal()` method creates a "sealed" object, which prevents new properties from being added to it, but allows existing properties to still be modified.

**Options Compared**

The benchmark compares the performance of two approaches:

1. **Normal Object**: Using a normal object for the `normal` variable.
2. **Object.seal()**: Creating an object using `Object.seal()` and passing the original object as an argument.

**Pros and Cons**

* **Normal Object**:
	+ Pros: Easy to create, no additional overhead.
	+ Cons: Properties can be added or removed at runtime, potentially impacting performance.
* **Object.seal()**:
	+ Pros: Prevents new properties from being added, which might improve performance for certain operations.
	+ Cons: Additional overhead due to the method call and argument passing.

**Library and Purpose**

There is no specific library used in this benchmark. The `Object` object is a built-in JavaScript object that provides various methods for manipulating objects.

**Special JS Feature or Syntax**

The benchmark uses the **`for...in` loop**, which iterates over an object's own enumerable properties. This loop is not unique to JavaScript and is commonly used in many programming languages.

**Other Alternatives**

If you were to reimplement this benchmark, consider using other approaches, such as:

* Using a different data structure, like an array or a map.
* Implementing your own property access mechanism (e.g., using getter/setter functions).
* Comparing the performance of different object creation methods, like `Object.create()` or `Array.prototype.slice()`.
* Adding additional operations to each test case, like sorting or filtering.

By considering alternative approaches and optimizing your code for specific use cases, you can gain a better understanding of how JavaScript objects work and improve your overall coding skills.

Related benchmarks:

Object vs Object.seal (version: 0)

JS Javascript Normal Object vs Object.seal performance

Comparing performance of: normal vs seal

Created: 5 years ago by: Registered User

Jump to the latest result

normal

seal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):