Benchmark: Array to object benchmark

Script Preparation code:

var array = [...Array(1000)].map(() => Math.random());

Tests:

for
const group = {}; for (var i = 0; i < array.length; i++) { array[i]; }
foreach
const group = {}; array.forEach(function(i) { const key = `${array[i]}`; group[key] = array[i]; });
some
const group = {}; array.some(function(i) { const key = `${array[i]}`; group[key] = array[i]; });
for..of
const group = {}; for (var i of array) { const key = `${array[i]}`; group[key] = array[i]; }
reduce
array.reduce(function(group, i) { const key = `${array[i]}`; group[key] = array[i]; return group; }, {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
some
for..of
reduce

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36

Browser/OS: Chrome 89 on Windows

View result in a separate tab

Test name	Executions per second
for	3663.8 Ops/sec
foreach	1974.6 Ops/sec
some	2074.1 Ops/sec
for..of	2133.0 Ops/sec
reduce	1996.6 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript benchmark that measures the performance of different approaches to iterate over an array and create an object with the elements as keys.

**Script Preparation Code**

The script preparation code is:
```javascript
var array = [...Array(1000)].map(() => Math.random());
```
This line creates an array of 1000 random numbers using the `Array` constructor, the spread operator (`...`), and the `map()` method. This will be used as the input data for the benchmark.

**Html Preparation Code**

The HTML preparation code is not specified in this case, so it is empty (`null`).

**Benchmark Definition**

The benchmark definition specifies that the goal is to create an object with the elements of the array as keys. The implementation details are specified in each test case:

* `for`: uses a traditional `for` loop to iterate over the array.
* `foreach`: uses the `forEach()` method to iterate over the array.
* `some`: uses the `some()` method to check if any element in the array passes a condition (not applicable in this case, as we're creating an object with all elements).
* `for..of`: uses the `for...of` loop to iterate over the array.
* `reduce`: uses the `reduce()` method to accumulate values and create an object.

**Library and Special JS Features**

None of these test cases use any external libraries. However, it's worth noting that some browsers (like Chrome) may have optimizations or built-in functions that can affect performance in certain scenarios.

**Performance Comparison**

The benchmark compares the execution time for each of the five approaches:

* `for`: uses a traditional loop to iterate over the array.
* `foreach`: uses the `forEach()` method, which is generally considered faster than traditional loops.
* `some`: uses the `some()` method, but it's not applicable in this case, as we're creating an object with all elements.
* `for..of`: uses a new loop syntax that's designed for iterating over arrays and other iterable objects.
* `reduce`: uses the `reduce()` method to accumulate values and create an object.

**Pros and Cons**

Here are some pros and cons of each approach:

* `for`:
	+ Pros: simple, well-known syntax, suitable for most use cases.
	+ Cons: can be slower than other methods due to the overhead of the loop.
* `foreach`:
	+ Pros: generally faster than traditional loops, simpler syntax.
	+ Cons: requires an additional function (the callback), which can add complexity.
* `for..of`:
	+ Pros: modern, efficient syntax that's designed for iterating over arrays and other iterable objects.
	+ Cons: may require some additional setup or learning to use effectively.
* `reduce`:
	+ Pros: can be used to accumulate values and create an object in a single pass.
	+ Cons: requires some understanding of the method's behavior and limitations.

**Other Alternatives**

Some alternative approaches that could have been tested include:

* Using `Array.prototype.forEach()` with a callback function
* Using a `while` loop or `do...while` loop to iterate over the array
* Using `Map` objects instead of plain objects
* Using other optimization techniques, such as caching or parallel processing.

It's worth noting that the specific alternatives used in this benchmark may not be the most efficient or effective approaches for all use cases. The goal is to provide a general comparison of different methods and encourage developers to explore and find the best solution for their specific needs.

Related benchmarks:

Array to object benchmark (version: 0)

Array to object benchmark

Comparing performance of: for vs foreach vs some vs for..of vs reduce

Created: 3 years ago by: Guest

Jump to the latest result

for

foreach

some

for..of

reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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