Benchmark: length 1 array indexOf vs includes vs some vs ===

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var temp = 'sausage'
var criteria = 'sausage'
var array = ['sausage']

Tests:

IndexOf
array.indexOf(criteria) !== 1
Includes
array.includes(criteria)
some
array.some(v => v === criteria)
===
temp === criteria

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
IndexOf
Includes
some
===

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's dive into explaining the benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that compares the performance of four different methods to check if an array contains a value: `indexOf`, `includes`, `some`, and the literal equality operator `===`.

**Options compared:**

1. **`indexOf`**: This method returns the index of the first occurrence of the specified value in the array, or -1 if it's not found.
2. **`includes`**: This method returns a boolean indicating whether the array includes the specified value.
3. **`some`**: This method returns a boolean indicating whether at least one element in the array satisfies the provided condition.
4. **`===`**: This is a literal equality operator that checks if two values are equal.

**Pros and Cons of each approach:**

1. **`indexOf`**:
	* Pros: Can be faster for arrays with a single element, as it only needs to check one index.
	* Cons: May be slower for larger arrays due to the need to traverse the entire array, and returns the index even if the value is not found.
2. **`includes`**:
	* Pros: More concise and readable than `indexOf`, and returns a boolean result directly.
	* Cons: May be slower than `indexOf` for very large arrays due to the overhead of iterating over the entire array, and may use more memory.
3. **`some`**:
	* Pros: Can be faster for larger arrays since it only needs to check one element, and returns a boolean result directly.
	* Cons: May be slower than `indexOf` or `includes` for small arrays due to the overhead of checking multiple conditions.
4. **`===`**:
	* Pros: Simple and concise, and returns a boolean result directly.
	* Cons: Can be slower than the other methods since it performs a full equality check between two values.

**Library used:**

The benchmark uses Lodash, a popular JavaScript utility library that provides many helper functions. In this case, the `lodash.some` function is being used to implement the `some` method.

**Special JS feature/syntax:**

There are no special JS features or syntax mentioned in the provided code. However, it's worth noting that modern JavaScript engines (like V8 in Chrome) use various optimizations and caching mechanisms to improve performance, which may affect the results of this benchmark.

**Other alternatives:**

If you want to implement a custom `indexOf`, `includes`, and `some` method for your own array class, you can consider using techniques like binary search or hash-based lookup. However, keep in mind that these methods may have different performance characteristics depending on the specific use case.

Here's an example of how you might implement a simple `indexOf` method using binary search:
```javascript
function indexOf(array, value) {
  let low = 0;
  let high = array.length - 1;

while (low <= high) {
    const mid = Math.floor((low + high) / 2);
    if (array[mid] === value) return mid;
    else if (array[mid] < value) low = mid + 1;
    else high = mid - 1;
  }
  return -1;
}
```
However, this implementation has a higher overhead due to the need for repeated divisions and comparisons.

Related benchmarks:

length 1 array indexOf vs includes vs some vs === (version: 0)

performance comparison of ways to find if an array contains a value

Comparing performance of: IndexOf vs Includes vs some vs ===

Created: 3 years ago by: Guest

Jump to the latest result

IndexOf

Includes

some

===

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):