Benchmark: Object.entries VS Object.keys for count

Script Preparation code:

function makeid() {
  var text = "";
  var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

  for (var i = 0; i < 5; i++)
    text += possible.charAt(Math.floor(Math.random() * possible.length));

  return text;
}

window.parentObj = {};

for (let i = 0; i < 100; i++) {
	window.parentObj[makeid()] = makeid();
}

Tests:

Object.entries
Object.entries(window.parentObj).length;
Object.keys
Object.keys(window.parentObj).length;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.entries
Object.keys

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided JSON represents two benchmark test cases: `Object.keys` and `Object.entries`. These tests measure the performance of accessing object properties using different methods.

**Options compared:**

There are three main options compared:

1. **Object.keys**: Returns an array of a given object's own enumerable property names.
2. **Object.entries**: Returns an array of a given object's own enumerable key-value pairs.
3. **Direct property access**: Directly accessing object properties using square brackets (e.g., `window.parentObj['makeid']`).

**Pros and Cons:**

* **Object.keys**:
	+ Pros: Generally faster than `Object.entries`, as it uses a lookup table to retrieve property names.
	+ Cons: Does not return key-value pairs, which may be desirable in certain situations.
* **Object.entries**:
	+ Pros: Returns key-value pairs, making it more versatile than `Object.keys`.
	+ Cons: May be slower than `Object.keys` due to the additional overhead of creating arrays and objects.
* **Direct property access**:
	+ Pros: Can be faster in certain situations, as it avoids the overhead of method calls and array creation.
	+ Cons: Less readable and maintainable, as it relies on manual property lookups.

**Library and purpose**

In this benchmark, `window.parentObj` is an object created using the provided script preparation code. It contains 100 properties with random keys (generated by the `makeid` function). The library used here is the built-in JavaScript object model.

**Special JS feature or syntax**

There are no special features or syntaxes mentioned in this benchmark. However, it's worth noting that some older browsers may have had different implementations of these methods or syntaxes.

**Other alternatives**

To improve performance in certain situations, developers might consider using alternative approaches, such as:

* Using a library like `lodash` to optimize object property access.
* Implementing custom lookup tables for frequently accessed properties.
* Utilizing SIMD (Single Instruction, Multiple Data) instructions to parallelize property lookups.

Keep in mind that the best approach depends on the specific use case and performance requirements.

Related benchmarks:

Object.entries VS Object.keys for count (version: 0)

Comparing performance of: Object.entries vs Object.keys

Created: 2 years ago by: Guest

Jump to the latest result

Object.entries

Object.keys

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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