Benchmark: Fastest way to check if object is empty2

Script Preparation code:

var xxx = {}
var yyy = {};
for (let i = 0; i < 10; ++i) {
  yyy[`key${i}`] = i;
}

function isEmpty(v) {
  for (const _ in xxx) { return false }
  return true;
}

Tests:

object.keys()
Object.keys(xxx) === 0 Object.keys(yyy) === 0
JSON.stringify()
JSON.stringify(xxx) === "{}" JSON.stringify(yyy) === "{}"
for in
isEmpty(xxx); isEmpty(yyy);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object.keys()
JSON.stringify()
for in

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0

Browser/OS: Chrome 120 on Windows

View result in a separate tab

Test name	Executions per second
object.keys()	3794875.0 Ops/sec
JSON.stringify()	1298410.6 Ops/sec
for in	3688980.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark test case on the MeasureThat.net website. The benchmark tests different approaches to check if an object is empty.

In this specific case, there are three test cases:

1. **object.keys()**: This test case measures how fast the `Object.keys()` method can return an array of keys for two empty objects (`xxx` and `yyy`).
2. **JSON.stringify()**: This test case measures how fast the `JSON.stringify()` method can convert two empty objects (`xxx` and `yyy`) to their JSON representations.
3. **for...in**: This test case measures how fast the `for...in` loop can check if an object is empty by iterating over its keys.

**Options compared**

The three options being tested are:

* Using the `Object.keys()` method to check if an object is empty
* Using the `JSON.stringify()` method to convert an object to its JSON representation and then checking if the resulting string is equal to `{}` (the JSON representation of an empty object)
* Using a custom `for...in` loop to iterate over the keys of an object and check if it's empty

**Pros and cons of each approach**

1. **object.keys()**:
	* Pros: Simple, efficient, and widely supported.
	* Cons: May not be as fast for very large objects due to its iterative nature.
2. **JSON.stringify()**:
	* Pros: Can handle complex objects with nested structures. However, it may involve additional overhead for objects with many keys or values.
	* Cons: May introduce unnecessary complexity and slower performance compared to `object.keys()` for simple cases.
3. **for...in**:
	* Pros: Allows for more control over the iteration process and can be adapted to specific use cases.
	* Cons: Can be slower due to its iterative nature and may not be as efficient as using built-in methods like `Object.keys()`.

**Library usage**

None of the test cases explicitly uses any external libraries. However, it's worth noting that some browsers or environments might provide additional functionality or optimizations for certain methods (e.g., `JSON.stringify()`).

**Special JS features or syntax**

The test case uses the `for...in` loop, which is a legacy feature from older JavaScript versions. While it's still supported in modern browsers and engines, its use is generally discouraged in favor of more modern iteration techniques like `for...of` or `Object.keys()`.

Related benchmarks:

Fastest way to check if object is empty2 (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 in

Created: 3 years ago by: Guest

Jump to the latest result

object.keys()

JSON.stringify()

for in

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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