Benchmark: 2 Map vs Push - MeasureThat.net

Script Preparation code:

var strs = Array.from(new Array(10000)).map(() => 'String concat. ')
var result = []
var result_two = []

Tests:

Push
for (let i = 0; i < strs.length; i++) { result.push(strs[i]) result_two.push(strs[i]) }
Join
result = strs.map((a) => a) result_two = strs.map((a) => a)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Push
Join

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Push	450.5 Ops/sec
Join	20172.3 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared, and discussed.

**Benchmark Overview**

The provided benchmark compares two approaches for appending elements to an array: using `push` and `map`. The test case consists of two individual tests: "Push" and "Join".

**Script Preparation Code**

The script preparation code is identical for both tests:
```javascript
var strs = Array.from(new Array(10000)).map(() => 'String concat. ');
var result = [];
var result_two = [];
```
This code creates an array `strs` containing 10,000 strings, each with the prefix "String concat. ". It then initializes two empty arrays: `result` and `result_two`.

**Test Cases**

There are two test cases:

1. **Push**: This test case iterates over the `strs` array using a traditional `for` loop and appends each string to `result` using the `push` method.
2. **Join**: This test case uses the `map` function to create a new array containing the same strings as `strs`, and assigns it to `result_two`. There is no apparent concatenation or iteration step; the strings are simply copied from `strs`.

**Comparison**

The benchmark tests which approach produces better performance:

* **Push**: This test case compares the performance of using `push` to append elements to an array. The goal is to determine if `push` is faster or slower than other methods.
* **Join**: This test case compares the performance of using `map` to create a new array and assign it to another variable.

**Library: Lodash**

The `map` function in both test cases uses the Lodash library. Lodash is a popular JavaScript utility library that provides various functions for working with arrays, objects, and other data structures. In this case, the `map` function is used to create a new array containing the same strings as `strs`.

**Special JavaScript Feature: None**

Neither of the test cases uses any special JavaScript features or syntax.

**Other Alternatives**

There are alternative approaches to appending elements to an array:

* **Splatting**: Instead of using `push`, you can use the spread operator (`...`) to append elements to an array.
* **Array.prototype.forEach**: You can use the `forEach` method instead of a traditional `for` loop to iterate over an array and append elements.

**Considerations**

When choosing between `push` and other methods, consider the following:

* **Performance**: In general, using `push` is faster than creating a new array or using other methods.
* **Memory allocation**: Using `map` can lead to memory allocation for a new array, which may be more expensive than using `push`.
* **Readability**: Choose the approach that is most readable and maintainable for your specific use case.

I hope this explanation helps you understand the benchmark and its results!

Related benchmarks:

2 Map vs Push (version: 0)

Comparing performance of: Push vs Join

Created: one year ago by: Guest

Jump to the latest result

Push

Join

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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