Benchmark: for-in vs object.keys steveruizok

Tests:

for-in
const CONTROL = { 'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5, 'f': 6, 'g': 7 } function getValue() { return 1 + Math.floor(Math.random() * 7) } const ARRAY = Array(1000); for (let i = 0; i < 1000; i++) { ARRAY[i] = { 'a': getValue(), 'b': getValue(), 'c': getValue(), 'd': getValue(), 'e': getValue(), 'f': getValue(), 'g': getValue() }; } const results = Array(1000); let item, result; for (let i = 0; i < 1000; i++) { result = {}; item = ARRAY[i] for (const key in item) { result[key] = item[key] === CONTROL[key]; }; results[i] = result; }
Object.keys
const CONTROL = { 'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5, 'f': 6, 'g': 7 } function getValue() { return 1 + Math.floor(Math.random() * 7) } const ARRAY = Array(1000); for (let i = 0; i < 1000; i++) { ARRAY[i] = { 'a': getValue(), 'b': getValue(), 'c': getValue(), 'd': getValue(), 'e': getValue(), 'f': getValue(), 'g': getValue() }; } const results = Array(1000); let item, result, keys, key; for (let i = 0; i < 1000; i++) { item = ARRAY[i]; result = {}; keys = Object.keys(item); for (let j =0; j < keys.length; j++) { key = keys[j]; result[key] = item[key] === CONTROL[key]; }; results[i] = result; }

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

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 break down the provided benchmark and its test cases.

**Benchmark Overview**

The measurement is between two JavaScript loops that iterate over an array of objects to compare values with a predefined control object (`CONTROL`). The loop variants being tested are:

1. `for-in`
2. Using `Object.keys()` to get an array of keys from the object

**For-In Loop**

In this loop, we iterate over each element in the `ARRAY` and create a new object (`item`) that contains the values generated by calling the `getValue()` function 7 times with increasing random numbers.

We then compare each value in `item` with its corresponding value in `CONTROL` using the `===` operator. This comparison is done inside another loop that runs for 1000 iterations.

**Object.keys() Loop**

In this loop, we also iterate over each element in the `ARRAY` and create a new object (`item`) as described above.

However, instead of using the `for-in` loop to compare values with `CONTROL`, we use `Object.keys()` to get an array of keys from the `item` object. We then use another loop to iterate over this array of keys and compare each value in `item` with its corresponding value in `CONTROL`.

**Library Used**

In both loops, the `Array` function is used to create arrays, which is a built-in JavaScript library.

**Special JS Feature/ Syntax**

There's no special or advanced JavaScript feature/syntax being tested here. The code uses standard JavaScript syntax and features like loops, object comparison, and array manipulation.

**Pros and Cons of Different Approaches**

1. `for-in` loop:
	* Pros: Can be faster for small arrays because it avoids the overhead of creating an array of keys.
	* Cons: May not be as efficient for large arrays because it has to iterate over all properties of the object, even if they're not actually being used in the comparison.
2. `Object.keys()` loop:
	* Pros: Can be faster for large arrays because it only iterates over the actual keys that are present in the object, avoiding any unnecessary iterations.
	* Cons: May have a higher overhead due to the creation of an array of keys.

**Considerations**

1. The performance difference between these two approaches depends on the size of the input data and the specific use case.
2. The `for-in` loop may be more suitable for iterating over objects with a large number of properties that are not actually being used in the comparison, while the `Object.keys()` loop may be more suitable for smaller datasets where key iteration is necessary.

**Other Alternatives**

There are other ways to compare values between two objects in JavaScript, such as using `every()`, `some()`, or iterating over an array of keys and comparing each value individually. However, these approaches would likely have similar performance characteristics to the `for-in` and `Object.keys()` loops.

For example:

* Using `every()`:
```javascript
function compareValues(control) {
  return ARRAY.every((item) => Object.values(item).every((value) => control[value] === value));
}
```
This approach uses the `every()` method to check if every value in each object matches its corresponding value in the control object. While this approach may be more concise, it has similar performance characteristics to the `for-in` and `Object.keys()` loops.

Ultimately, the choice of loop variant depends on the specific requirements of your use case and performance considerations.

Related benchmarks:

for-in vs object.keys steveruizok (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):