Benchmark: Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without arraya s.d..

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
const newObj = {}; for (const [k,v] of Object.entries(window.parentObj)) { newObj[k] = v; }
Object.keys
const newObj = {}; for (const k of Object.keys(window.parentObj)) { newObj[k] = window.parentObj[k]; }

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:

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

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmark and explain what is being tested, along with the pros and cons of each approach.

**Benchmark Definition**

The benchmark tests three approaches to iterating over an object:

1. `Object.entries`
2. `Object.keys`
3. `Object.keys` with an extra array (i.e., using `window.parentObj` which contains multiple arrays)

These functions are used to iterate over the properties of an object, where each property is represented as a key-value pair.

**Approach 1: `Object.entries`**

This approach uses the `entries()` method, which returns an iterator that yields tuples containing the key-value pairs of the object.

Pros:

* More memory-efficient than using `Object.keys`, as it only iterates over the keys and values in a single pass.
* Can be more efficient for large objects, as it avoids creating intermediate arrays.

Cons:

* May not work well with older browsers that don't support the `entries()` method.
* Requires modern JavaScript features (ECMAScript 2015+).

**Approach 2: `Object.keys`**

This approach uses the `keys()` method, which returns an array of the object's keys. The iteration is done using a for loop.

Pros:

* Wide browser support, as it has been supported since ECMAScript 2009.
* Simple and easy to understand.

Cons:

* Creates an intermediate array, which can be memory-inefficient for large objects.
* May be slower than `Object.entries` due to the extra overhead of creating and iterating over the array.

**Approach 3: `Object.keys` with an extra array**

This approach uses a similar approach as above, but wraps the `window.parentObj` in an array using `[]`. This creates a nested array structure that still allows for iteration using `Object.keys`.

Pros:

* Wide browser support (same as `Object.keys`).
* Can be more efficient than creating a new object with properties.

Cons:

* Creates unnecessary extra complexity and memory usage due to the nested array.
* May be slower than other approaches due to the overhead of creating and accessing the nested array.

**Other Considerations**

When choosing between these approaches, consider the following factors:

* Memory efficiency: If you're working with large objects, `Object.entries` may be a better choice.
* Browser support: If you need to support older browsers, `Object.keys` might be a safer option.
* Code complexity and readability: `Object.keys` is generally easier to understand and write, but `Object.entries` can be more concise.

**Library Usage**

The benchmark uses the `window.parentObj` which contains an array of strings. This suggests that the library being tested (in this case, likely a framework or application) is creating and storing multiple objects with properties.

**Special JavaScript Feature/Syntax**

There are no specific special features or syntaxes being used in these benchmarks. They focus on testing the performance of the three approaches to iterating over an object.

Related benchmarks:

Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without arraya s.d.. (version: 0)

Comparing performance of: Object.entries vs Object.keys

Created: 3 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):