Benchmark: Fastest way to check if object is empty using length 2

Script Preparation code:

var xxx = {}

Tests:

object.keys()
Object.keys(xxx) === 0
JSON.stringify()
JSON.stringify(xxx) === "{}"
For loop
for (var key in xxx) { if (hasOwnProperty.call(value, key)) { return false; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object.keys()
JSON.stringify()
For loop

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and analyze the provided benchmark definition.

**Benchmark Definition**

The benchmark definition is a JSON object that contains the details of the test case. Here's what it tells us:

* The test aims to find the fastest way to check if an object is empty using a length 2 approach.
* The script preparation code is `var xxx = {}`, which creates an empty object named `xxx`.
* There are three individual test cases:
	1. `object.keys()`: Checks if the object has any keys using the `keys()` method.
	2. `JSON.stringify(xxx) === "{}"`: Checks if the JSON string representation of the object is equal to `{}`.
	3. `For loop`: Uses a for loop to check if the object has any properties.

**Test Case Analysis**

Let's analyze each test case:

1. **`object.keys()`**: This method returns an array of all the property names contained in the object. If the object is empty, it returns an empty array (`[]`). The benchmark measures how fast this method can check if the object has any keys.
2. **`JSON.stringify(xxx) === "{}",`**: JSON stringification creates a string representation of the object. If the object is empty, it should be equal to `{}`. The benchmark measures how fast this method can compare the JSON string with an empty string.
3. **`For loop`**: This test case uses a for loop to check if the object has any properties. It iterates over each property in the object and checks if the property is present using `hasOwnProperty.call(value, key)`. The benchmark measures how fast this method can iterate over the object's properties.

**Library and Special JS Features**

* None of the test cases use a specific JavaScript library.
* There are no special JavaScript features or syntax used in these test cases.

**Pros and Cons of Different Approaches**

Here are some pros and cons of each approach:

1. **`object.keys()`**:
	* Pros: Fast, simple, and widely supported.
	* Cons: May not work correctly with objects that have non-enumerable properties.
2. **`JSON.stringify(xxx) === "{}",`**:
	* Pros: Works well with most objects, but can be slow for very large objects due to stringification overhead.
	* Cons: Not suitable for objects with non-serializable properties or large numbers of nested objects.
3. **`For loop`**:
	* Pros: Can handle complex object structures and non-enumerable properties.
	* Cons: May be slower than the other two approaches, especially for large objects.

**Other Alternatives**

Some alternative methods to check if an object is empty include:

1. `Object.keys(xxx).length === 0` (similar to `object.keys()`, but uses a direct property access)
2. `xxx.length === 0` (works well with objects, but may not work correctly with non-array-like objects)
3. `Object.getOwnPropertyNames(xxx).length === 0` (uses `getOwnPropertyNames()` to check for non-enumerable properties)

These alternatives can be used as part of the benchmark to provide more comprehensive results.

I hope this explanation helps you understand the JavaScript microbenchmark and its different test cases!

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
object.keys()	10189637.0 Ops/sec
JSON.stringify()	8160203.0 Ops/sec
For loop	24137856.0 Ops/sec

Related benchmarks:

Fastest way to check if object is empty using length 2 (version: 0)

You don't need to make add for loops in your test scenarios, the benchmark does it itself.

Comparing performance of: object.keys() vs JSON.stringify() vs For loop

Created: one month ago by: Guest

Jump to the latest result

object.keys()

JSON.stringify()

For loop

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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