Benchmark: Spread operator vs apply

Script Preparation code:

function test() { console.log(arguments[arguments.length - 1]); }
var using = (new Array(200)).fill(null).map((e, i) => (i));

Tests:

spread
test(...using);
apply
test.apply(null, using)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
apply

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The benchmark is designed to compare two ways of calling a function with arbitrary arguments dynamically: using the spread operator (`...`) and `apply()`. The goal is to determine which approach is faster.

**Script Preparation Code**

The script preparation code defines a simple function `test()` that takes an array of arguments as input. It then uses the spread operator to extract the last argument from the array, or `apply()` with `null` as the context and the `using` array as the arguments.

```javascript
function test() { console.log(arguments[arguments.length - 1]); }

var using = (new Array(200)).fill(null).map((e, i) => (i));
```

The `using` array is created by mapping over an array of 200 elements with values from 0 to 199. This creates a large array that will be passed as arguments to the `test()` function.

**Test Cases**

There are two test cases:

1. **"spread"`: This test case uses the spread operator (`...`) to call the `test()` function with the `using` array as arguments.
2. **"apply"`: This test case uses `apply()` to call the `test()` function with `null` as the context and the `using` array as arguments.

**Library Used**

None, this benchmark does not rely on any external libraries.

**Special JS Feature/Syntax**

The spread operator (`...`) is a feature introduced in ECMAScript 2015. It allows you to pass an array of values as separate arguments to a function.

**Pros and Cons of Different Approaches**

1. **Spread Operator (`...`)**:
	* Pros: concise, readable, and efficient.
	* Cons: performance might be slower compared to `apply()`, especially for large arrays.
2. **`apply()`**:
	* Pros: can be faster than the spread operator, as it avoids creating a new array.
	* Cons: less concise and readable, requires manual management of the context.

**Other Considerations**

When considering this benchmark, keep in mind that:

* The size of the `using` array (200 elements) is significant, which may impact performance differences between the two approaches.
* Modern JavaScript engines like V8 (used by Chrome) are optimized for performance and might mitigate any performance differences between these two approaches.

**Alternatives**

Other alternatives to compare in a similar benchmark could be:

1. **Destructuring assignment**: Instead of using `apply()`, you could use destructuring assignment to extract the arguments from the array.
2. **`rest parameter` syntax**: You could use the rest parameter syntax (`...args`) instead of the spread operator, which might offer better performance for large arrays.

To prepare a similar benchmark, you would need to:

1. Define a new function with arbitrary arguments dynamically.
2. Create an array of values that will be passed as arguments to the function.
3. Use different methods (e.g., `apply()`, spread operator, destructuring assignment, rest parameter syntax) to call the function and compare their performance.

By running such benchmarks, you can gain insights into the performance characteristics of different JavaScript features and writing styles.

Latest run results:

Run details: (Test run date: 2 days ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.1

View result in a separate tab

Test name	Executions per second
spread	1048203.6 Ops/sec
apply	1394209.6 Ops/sec

Related benchmarks:

Spread operator vs apply (version: 0)

Compare the differing ways you can call a function with arbitrary arguments dynamically

Comparing performance of: spread vs apply

Created: 5 years ago by: Guest

Jump to the latest result

spread

apply

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):