Benchmark: Array Test 1234 - MeasureThat.net

Script Preparation code:

function getRandomInt(max) {
  return Math.floor(Math.random() * Math.floor(max));
}

var arr = [];
for(var i = 0; i < 5000; i++){
  arr.push({value:getRandomInt(100)});
}

Tests:

Array isArray
Array.isArray(arr)
Obj check
!!arr && arr.constructor === Array;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array isArray
Obj check

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case on the MeasureThat.net website. The benchmark tests two different approaches to determine whether an object is an array.

**Script Preparation Code**

The script preparation code defines a function `getRandomInt(max)` that generates a random integer between 0 and `max`. This function is used later in the benchmark.

```javascript
function getRandomInt(max) {
  return Math.floor(Math.random() * Math.floor(max));
}
```

The script then creates an array `arr` with 5000 elements, each containing a random integer value between 0 and 100. The purpose of creating this array is to test the JavaScript engine's ability to perform array-related operations.

```javascript
var arr = [];
for (var i = 0; i < 5000; i++) {
  arr.push({ value: getRandomInt(100) });
}
```

**Html Preparation Code**

The HTML preparation code is empty, indicating that no HTML-specific tests are being performed.

```javascript
"<!DOCTYPE html><html></html>"
```

**Individual Test Cases**

There are two test cases:

1. **Array.isArray(arr)**

This test case checks whether the `arr` variable is an array using the `Array.isArray()` function. The expected output is a boolean value indicating whether `arr` is an array.

2. **!!arr && arr.constructor === Array;**

This test case uses a combination of logical operators to check two conditions:

* `!!arr`: This checks if `arr` is truthy (i.e., not null or undefined).
* `&& arr.constructor === Array;`: If `arr` is truthy, this checks if its constructor property is equal to the Array constructor function.

The expected output is a boolean value indicating whether both conditions are true.

**Pro and Cons of Each Approach**

1. **Array.isArray(arr)**

Pros:

* Simple and straightforward.
* Easy to understand for most developers.

Cons:

* May not work correctly in older browsers or engines that don't support the `Array.isArray()` function.

2. **!!arr && arr.constructor === Array;**

Pros:

* More robust, as it checks for both truthiness and type equality.
* Can handle cases where `arr` is a null or undefined value.

Cons:

* Less readable due to the use of logical operators.
* May require more time for interpretation by some developers.

**Other Considerations**

The benchmark also includes metadata about the test runner, such as the browser name, version, platform, and operating system. This information can be useful in understanding how different browsers or engines perform on this specific benchmark.

If you're interested in exploring other alternatives, there are several approaches to determining whether an object is an array:

* Using `typeof arr === "object"` (although this has its own set of pros and cons)
* Implementing a custom check using the `Object.prototype.toString()` method
* Using a library like Lodash's `isArray` function

However, these alternatives are not included in the provided benchmark JSON.

Related benchmarks:

Array Test 1234 (version: 0)

Comparing performance of: Array isArray vs Obj check

Created: 4 years ago by: Guest

Jump to the latest result

Array isArray

Obj check

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):