Benchmark: Array includes 20190424

Script Preparation code:

var arr = new Array(1000).fill(null);

Tests:

for
for (let i = 0; i < arr.length; i++) { if (i === 500) { return true; } }
optimized for
for (let i = 0, l = arr.length; i < l; i++) { if (i === 500) { return true; } }
includes
return arr.includes((v, i) => i === 500);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
optimized for
includes

Fastest: N/A

Slowest: N/A

Latest run results:

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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 its test cases.

**Overview**

The benchmark is designed to measure the performance of JavaScript arrays using different methods: traditional `for` loops, optimized `for` loops, and the `includes()` method with a callback function. The goal is to compare the execution speed of these approaches on various browsers and devices.

**Benchmark Definition JSON**

The benchmark definition provides some basic information:

* **Name**: "Array includes 20190424" - This is a unique identifier for the benchmark.
* **Description**: None - There's no description provided for this benchmark.
* **Script Preparation Code**: `var arr = new Array(1000).fill(null);` - This code creates an array of 1000 null values.
* **Html Preparation Code**: None - There's no HTML preparation code provided.

**Test Cases**

There are three test cases:

1. **"for"`**
This test case uses a traditional `for` loop to check if the index `i` is equal to 500 in the array. The loop iterates over the entire array, which might not be efficient.
2. **"optimized for"`
This test case uses an optimized `for` loop, which is similar to the previous one but with a few key differences:
	* `let i = 0; l = arr.length;` - This line initializes the loop variable and sets the length of the array to the current index.
	* The loop iterates until `i < l`, which avoids unnecessary iterations.
3. **"includes"`
This test case uses the `includes()` method with a callback function to check if the index `i` is equal to 500 in the array.

**Library and Special JS Features**

In this benchmark, there's no explicit library mentioned. However, some features are used:

* The `includes()` method is a standard JavaScript method introduced in ECMAScript 2019.
* The `let` keyword with the `const` initialization syntax (`const i = 0;`) is a modern JavaScript feature.

**Pros and Cons of Different Approaches**

Here's a brief analysis of each approach:

1. **Traditional "for"` loop:
	* Pros: Simple to implement, well-known algorithm.
	* Cons: May iterate over unnecessary elements, less efficient than optimized loops or array methods like `includes()`.
2. **Optimized "for" loop**:
	* Pros: More efficient by avoiding unnecessary iterations, uses modern JavaScript syntax.
	* Cons: Requires knowledge of the loop variable and length initialization, might be harder to understand for some developers.
3. **`includes()` method with callback function**:
	* Pros: Modern, efficient, and easy to implement.
	* Cons: May have performance issues if not implemented correctly (e.g., using `Array.prototype.includes()`), requires knowledge of the callback function.

**Other Alternatives**

Some alternative approaches for checking if an index is equal to a specific value in an array include:

* Using `Array.prototype.findIndex()`: This method returns the index of the first element that satisfies the condition, or -1 if no such element exists.
* Using `Array.prototype.indexOf()`: This method returns the index of the first occurrence of the specified value, or -1 if not found.

These alternative approaches might have different performance characteristics and are worth considering in specific use cases.

Related benchmarks:

Array includes 20190424 (version: 0)

Comparing performance of: for vs optimized for vs includes

Created: 7 years ago by: Guest

Jump to the latest result

for

optimized for

includes

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):