Benchmark: for-in vs object.keys map array 2

Script Preparation code:

var obj = {
    '1': 1,
    '2': 1,
    '3': 1,
    '4': 1,
    '5': 1,
    '6': 1,
    '7': 1,
    '8': 1,
    '9': 1,
    '10': 1
};

Tests:

for-in
for (var i=10000; i > 0; i--) { const arr = []; for (var key in obj) { arr.push(+key); } }
Object.keys
for (var i=10000; i > 0; i--) { Object.keys(obj).map(key => +key); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for-in
Object.keys

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.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark measures the performance of two approaches: `for-in` loop and using `Object.keys()` with `map()`. We'll break down each approach, its pros and cons, and other considerations.

**Approach 1: `for-in` Loop**

The first test case uses a `for-in` loop to iterate over an object's keys and push them into an array.
```javascript
for (var key in obj) {
    arr.push(+key);
}
```
This approach is simple and easy to understand. However, it has some drawbacks:

Pros:

* Easy to implement and understand
* No additional libraries or dependencies required

Cons:

* Can be slower due to the overhead of property access and string conversion (`+key`)
* May not be suitable for large datasets or objects with many properties

**Approach 2: Using `Object.keys()` with `map()`**

The second test case uses `Object.keys()` to get an array of keys from the object, followed by a `map()` function to convert each key to a number.
```javascript
Object.keys(obj).map(key => +key);
```
This approach is more efficient than the `for-in` loop:

Pros:

* Faster due to the optimized implementation of `Object.keys()` and `map()`
* Suitable for large datasets or objects with many properties

Cons:

* Requires the use of built-in methods (`Object.keys()` and `map()`)
* May require additional imports or libraries (although it's often included in modern JavaScript environments)

**Library: `Object.keys()`**

`Object.keys()` is a built-in method in JavaScript that returns an array of a given object's own enumerable property names. It's commonly used to get an array of keys from an object.

In this benchmark, `Object.keys()` is used to get the array of keys, which is then piped into the `map()` function to convert each key to a number.

**Special JS Feature/Syntax: None**

There are no special JavaScript features or syntaxes being tested in this benchmark. It's focused on comparing two basic approaches to iterating over an object's keys.

**Other Alternatives**

If you want to explore alternative approaches, here are some options:

* Using `forEach()` instead of `for-in` loop
* Using `reduce()` instead of `map()`
* Using a library like Lodash to simplify the iteration process

Keep in mind that each approach has its pros and cons, and the best choice depends on your specific use case and performance requirements.

Related benchmarks:

for-in vs object.keys map array 2 (version: 0)

Comparing performance of: for-in vs Object.keys

Created: 3 years ago by: Guest

Jump to the latest result

for-in

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):