Benchmark: Object.entries VS Object.keys VS Object.values

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 = {}; Object.entries(window.parentObj).forEach(([k, v], i) => { if ((i % 2) === 0) { newObj[k] = v; } });
Object.keys
const newObj = {}; Object.keys(window.parentObj).forEach((k, i) => { if ((i % 2) === 0) { newObj[k] = window.parentObj[k]; } });
Object.values
const newObj = {}; Object.values(window.parentObj).forEach((v, i) => { if ((i % 2) === 0) { newObj[i] = window.parentObj[v]; } });
Object.entries2
const newObj = {}; Object.entries(window.parentObj).forEach(([k, v], i) => { if ((i % 2) === 0) { newObj[i] = v; } });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.entries
Object.keys
Object.values
Object.entries2

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 break down the provided benchmark and its test cases.

**Benchmark Purpose**

The benchmark is designed to compare the performance of three different methods for accessing and manipulating object properties in JavaScript: `Object.entries()`, `Object.keys()`, and `Object.values()`.

These methods are used to iterate over an object's key-value pairs. However, when using these methods, you need to decide how to handle the case where the object is not iterable (e.g., a non-object value). In this benchmark, the test cases aim to compare different approaches for handling such scenarios.

**Comparison Options**

There are three main comparison options:

1.  **`Object.entries()`**: This method returns an array of a given object's own enumerable string-keyed property [key, value] pairs. The code uses `forEach()` with `[k, v], i` to iterate over the pairs and access specific values.
2.  **`Object.keys()`**: This method returns an array of all the accessible keys for an object. It is used in this benchmark with `(k, i)` to iterate over the key-value pairs where `i` is an index.
3.  **`Object.values()`**: Similar to `Object.entries()`, but it only returns the values instead of both keys and values. In the code snippet, it's used with `(v, i)` as the iteration parameters.

**Pros and Cons**

*   *Consistency*: All three methods are designed to work with iterable objects, which can lead to inconsistent performance in non-iterable cases.
    *   Using `Object.entries()` or `Object.values()` works well when the object is iterable because it avoids the overhead of parsing keys. However, when dealing with non-iterable values, this method will produce errors.
    *   The `Object.keys()` approach has some limitations as well; if the object doesn't have any numeric key, it won't include that key in its result set, and may cause performance issues for large objects.

**Pros of `Object.entries()`**:

*   It includes all properties in both keys and values.
*   If the value is not iterable, you can just ignore it as with Object.keys().

Related benchmarks:

Object.entries VS Object.keys VS Object.values (version: 0)

Comparing performance of: Object.entries vs Object.keys vs Object.values vs Object.entries2

Created: 3 years ago by: Guest

Jump to the latest result

Object.entries

Object.keys

Object.values

Object.entries2

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):