Benchmark: spread vs arr - MeasureThat.net

Tests:

spread
const spread = [1, 2, ...['a', true, 2]]
arr
const spread = [1, 2].push('a', true, 2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
arr

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/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
spread	54934952.0 Ops/sec
arr	74383480.0 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark compares two ways of creating arrays in JavaScript: using the spread operator (`...`) and using the `push()` method.

**Options Compared:**

* **`spread`**: This approach uses the spread operator to combine multiple arrays into a single new array. In this case, it's taking an array `[1, 2]` and adding elements from another array `['a', true, 2]`.
* **`arr`**: This approach uses the `push()` method to add elements one by one to an existing array.  It starts with `[1, 2]` and then adds `'a'`, `true`, and `2` sequentially.

**Pros and Cons:**

* **Spread Operator (`...`)**:
    * **Pros:** More concise and readable syntax, can be used to combine multiple arrays or iterables efficiently.
    * **Cons:** Can potentially create more garbage (temporary arrays) depending on the structure of the data being spread.  Performance-wise it might not always be the fastest option, as it involves a deeper copy operation.

* **`push()` Method**:
    * **Pros:** More traditional approach, can modify an existing array in place, potentially slightly faster for adding elements one by one.
    * **Cons:** Less readable syntax when adding multiple elements, requires iterating through the elements individually.

**Other Considerations:**

The choice between these methods often comes down to personal preference and the specific use case. For simple cases like this, the performance difference might be negligible. However, in more complex scenarios with large arrays or frequent modifications, optimizing for memory usage or execution speed could become crucial.

**Alternatives:**

* **Array Concatenation (`+`)**: 
   ```javascript
   const spread = [1, 2].concat(['a', true, 2]); // Similar to using the spread operator
   ```
   While readable, it can be less efficient for large arrays due to potential array copying.

* **`unshift()` Method**: If you want to add elements to the *beginning* of an array instead of the end, `unshift()` is a suitable alternative.

Related benchmarks:

spread vs arr (version: 0)

aaa

Comparing performance of: spread vs arr

Created: 6 years ago by: Guest

Jump to the latest result

spread

arr

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):