Benchmark: concat vs push in javascript 2

Tests:

concat
var array = [] for(var i = 0; i < 1000; i++) { array = array.concat(i) }
push
var array = [] for(var i = 0; i < 1000; i++) { array.push(i) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat
push

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark and explain what's being tested, compared, and discussed.

**Benchmark Purpose:**
The main objective of this benchmark is to compare the performance of two different ways to append elements to an array in JavaScript: `concat` and `push`.

**Script Preparation Code:**
There is no script preparation code provided for this benchmark. This means that the test cases are simple and don't require any setup or initialization.

**Html Preparation Code:**
There is also no html preparation code provided, which suggests that the benchmark only measures JavaScript performance and doesn't involve any HTML-related overhead.

**Test Cases:**
The two test cases are:

1. `concat`: This test case uses the `concat` method to append numbers from 0 to 999 to an empty array.
2. `push`: This test case uses the `push` method to append numbers from 0 to 999 to an empty array.

**Library and Purpose:**
There is no explicit library mentioned in this benchmark, but it's likely that the benchmark relies on the built-in JavaScript `Array` prototype methods (`concat` and `push`) or a specific testing framework that provides these methods.

**Special JS Features/Syntax:**
There are no special JS features or syntax explicitly used in this benchmark. However, note that some modern browsers (like Chrome) use a technique called "just-in-time" compilation, which can affect performance measurements. MeasureThat.net likely accounts for this by running the benchmarks multiple times and averaging the results.

**Comparison of Approaches:**
The comparison between `concat` and `push` methods is based on their performance characteristics:

* **Push**: Pushing elements onto an array using the `push` method is generally faster than concatenating arrays. This is because pushing doesn't create a new array object; instead, it modifies the existing one by appending the element to its end.
* **Concat**: Concatenating arrays using the `concat` method creates a new array object that contains all elements from both arrays. This can lead to slower performance compared to pushing, especially for large datasets.

**Pros and Cons:**

Pros of using `push`:

* Faster performance
* Less memory allocation overhead

Cons of using `push`:

* Requires multiple push calls per element (e.g., `array.push(i), array.push(j)`)
* May not be suitable for situations where the entire array needs to be modified at once

Pros of using `concat`:

* Easier to implement and understand
* Suitable for situations where the entire array needs to be modified at once

Cons of using `concat`:

* Slower performance due to the creation of a new array object
* More memory allocation overhead

**Other Alternatives:**

If you need to append elements to an array in JavaScript, some alternative approaches include:

1. Using a `for...of` loop and pushing elements onto the array: `array = []; for (const value of arr) { array.push(value); }`
2. Using a library like Lodash's `compact` function: `_([].concat(arr)).flatten()`
3. Creating an array using the spread operator (`[...]`) followed by push: `[...[], ...arr]`

However, these alternatives might not always be faster or more efficient than the original `push` and `concat` methods.

Overall, this benchmark provides a simple and informative comparison of two common JavaScript array modification techniques. It highlights the importance of considering performance characteristics when choosing an approach for specific use cases.

Related benchmarks:

concat vs push in javascript 2 (version: 0)

Comparing performance of: concat vs push

Created: 5 years ago by: Guest

Jump to the latest result

concat

push

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):