Benchmark: Small but maybe empty Array versus Small Object (Access wise)

Script Preparation code:

var indexes = [];
var array = [];
var object = {};
for (let i = 0; i < 10; i++) {
    const index = Math.floor (Math.random () * 10);
    array[index] = 1;
    object[index] = 1;
    indexes.push (index);
}

Tests:

Array
let sum = 0; for (let i = indexes.length - 1 ; i >= 0 ; i--) { const index = indexes[i]; sum += array[index]; }
Object
let sum = 0; for (let i = indexes.length - 1 ; i >= 0 ; i--) { const index = indexes[i]; sum += object[index]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array
Object

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.

Let's break down the provided benchmark and explain what's being tested, compared, and their pros/cons.

**Benchmark Overview**

The benchmark compares two approaches for accessing data in small arrays or objects: using an array index (`array[index]`) versus using an object property key (`object[index]`).

**Script Preparation Code**

The script preparation code generates a small random array `array` and object `object`, each with 10 elements. The code also creates an array of indices `indexes` containing the same values.

```javascript
var indexes = [];
var array = [];
var object = {};

for (let i = 0; i < 10; i++) {
    const index = Math.floor(Math.random() * 10);
    array[index] = 1;
    object[index] = 1;
    indexes.push(index);
}
```

**Html Preparation Code**

There is no HTML preparation code provided, so we'll assume it's not relevant to this benchmark.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **Array**: This test case uses the array index approach (`array[index]`) to access elements in the `array`.
```javascript
let sum = 0;
for (let i = indexes.length - 1; i >= 0; i--) {
    const index = indexes[i];
    sum += array[index];
}
```

2. **Object**: This test case uses the object property key approach (`object[index]`) to access elements in the `object`.
```javascript
let sum = 0;
for (let i = indexes.length - 1; i >= 0; i--) {
    const index = indexes[i];
    sum += object[index];
}
```

**Pros and Cons of Each Approach**

* **Array Indexing**:
	+ Pros: Can be faster for small arrays, as it uses a simple array lookup.
	+ Cons: May not be suitable for large arrays or objects due to the overhead of iterating over the entire array.
* **Object Property Keying**:
	+ Pros: Can be more efficient for accessing elements in an object, especially if the object is sparse (i.e., has many empty properties).
	+ Cons: Can lead to slower performance for small objects, as the V8 engine needs to iterate over the object's prototype chain.

**Library and Purpose**

The `indexes` array is used as a helper data structure to keep track of the indices being accessed. It's not a library per se, but rather an internal implementation detail.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. The focus is on comparing two basic access patterns for small arrays and objects.

**Alternative Approaches**

Other approaches to accessing data in small arrays or objects might include:

* Using `Set` or `Map` data structures, which can provide faster lookup times than arrays.
* Utilizing optimized built-in functions like `at()` or `in` for array and object access, respectively.
* Implementing custom caching mechanisms or memoization techniques to improve performance.

However, the benchmark's focus on comparing simple indexing approaches makes these alternatives less relevant.

Related benchmarks:

Small but maybe empty Array versus Small Object (Access wise) (version: 0)

Comparing performance of: Array vs Object

Created: 2 years ago by: Guest

Jump to the latest result

Array

Object

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):