Benchmark: arguments vs array arg

Script Preparation code:

function test() {
    var v = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        v[_i] = arguments[_i];
    }
  var different = false;
  for (var j = 0; j < v.length; j++) {
    if (j % 2 === 0) different = true;
  }
  return different;
}


function test2(v) {
  var different = false;
  for (var j = 0; j < v.length; j++) {
    if (j % 2 === 0) different = true;
  }
  return different;
}

​x
 
function test() {    var v = [];    for (var _i = 0; _i < arguments.length; _i++) {        v[_i] = arguments[_i];    }  var different = false;  for (var j = 0; j < v.length; j++) {    if (j % 2 === 0) different = true;  }  return different;}​​function test2(v) {  var different = false;  for (var j = 0; j < v.length; j++) {    if (j % 2 === 0) different = true;  }  return different;}​

Tests:

arguments

for(var i = 0; i < 10000; i++) {
  test(i, i + 1, i + 2, i + 3, i + 4, i + 5);
}

 
for(var i = 0; i < 10000; i++) {  test(i, i + 1, i + 2, i + 3, i + 4, i + 5);}

array arg

for(var i = 0; i < 10000; i++) {
  test2([i, i + 1, i + 2, i + 3, i + 4, i + 5]);
}

 
for(var i = 0; i < 10000; i++) {  test2([i, i + 1, i + 2, i + 3, i + 4, i + 5]);}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
arguments
array arg

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2025 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:58.0) Gecko/20100101 Firefox/58.0

Browser/OS: Firefox 58 on Mac OS X 10.12

View result in a separate tab

Test name	Executions per second
arguments	2481.7 Ops/sec
array arg	10435.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

What is being tested?

The provided JSON represents two JavaScript microbenchmarks, arguments vs array arg, which compare the performance of two approaches to pass arguments to a function:

arguments: This approach uses the built-in arguments object in JavaScript, which contains an array-like object containing the values passed to a function.
array arg: This approach passes an array literal as the first argument to the function.

Options compared

The benchmark tests the performance of two approaches: using arguments and passing an array literal.

Pros and Cons of each approach

Using arguments:
- Pros:
  - Simple and straightforward.
  - Native JavaScript syntax, so no additional libraries are required.
- Cons:
  - May have slower performance due to the overhead of creating an array-like object.
Passing an array literal (array arg):
- Pros:
  - Can be faster since arrays can be optimized by the JavaScript engine.
- Cons:
  - Requires additional library support (in this case, none is mentioned) or a specific function signature.

Library usage

There is no explicit mention of any libraries being used in these benchmark tests. The arguments approach relies on native JavaScript syntax, and the array arg approach uses an array literal, which does not require any additional library support.

Special JS features or syntax

There are no special JS features or syntax mentioned that would require specific handling or configuration for this benchmark.

Other alternatives

If you're looking to optimize performance by avoiding the overhead of creating an array-like object using arguments, consider passing an array literal as an argument, like in the array arg approach. However, keep in mind that this might still depend on the browser and JavaScript engine's optimization capabilities.

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided JSON represents two JavaScript microbenchmarks, `arguments vs array arg`, which compare the performance of two approaches to pass arguments to a function:

1.  **`arguments`**: This approach uses the built-in `arguments` object in JavaScript, which contains an array-like object containing the values passed to a function.
2.  **`array arg`**: This approach passes an array literal as the first argument to the function.

**Options compared**

The benchmark tests the performance of two approaches: using `arguments` and passing an array literal.

**Pros and Cons of each approach**

*   **Using `arguments`**:
    *   Pros:
        *   Simple and straightforward.
        *   Native JavaScript syntax, so no additional libraries are required.
    *   Cons:
        *   May have slower performance due to the overhead of creating an array-like object.
*   **Passing an array literal** (`array arg`):
    *   Pros:
        *   Can be faster since arrays can be optimized by the JavaScript engine.
    *   Cons:
        *   Requires additional library support (in this case, none is mentioned) or a specific function signature.

**Library usage**

There is no explicit mention of any libraries being used in these benchmark tests. The `arguments` approach relies on native JavaScript syntax, and the `array arg` approach uses an array literal, which does not require any additional library support.

**Special JS features or syntax**

There are no special JS features or syntax mentioned that would require specific handling or configuration for this benchmark.

**Other alternatives**

If you're looking to optimize performance by avoiding the overhead of creating an array-like object using `arguments`, consider passing an array literal as an argument, like in the `array arg` approach. However, keep in mind that this might still depend on the browser and JavaScript engine's optimization capabilities.

Related benchmarks:

arguments vs array arg (version: 0)

Comparing performance of: arguments vs array arg

Created: 7 years ago by: Guest

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