Benchmark: Array.find vs Array.indexOf vs Array.filter vs Map.has

Script Preparation code:

let array = [];
for (var i=0; i<300; ++i) {
  	array.push('00' + i);
}

function hasWithFind(needle) {
	return array.find((entry) => entry == needle) !== undefined;
}

function hasWithIndexOf(needle) {
	return array.indexOf(needle) !== -1;
}

function hasWithFilter(needle) {
	return array.filter((entry) => entry == needle).length > -1;
}

let map = {};
array.forEach(item => map[item] = true);

function hasWithMap(needle) {
	return needle in map;
}

Tests:

find
for (var i=0; i<100; ++i) { hasWithFind('404'); }
indexOf
for (var i=0; i<100; ++i) { hasWithIndexOf('404'); }
filter
for (var i=0; i<100; ++i) { hasWithFilter('404'); }
map
for (var i=0; i<100; ++i) { hasWithMap('404'); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
find
indexOf
filter
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
find	41397.4 Ops/sec
indexOf	49420.9 Ops/sec
filter	30091.1 Ops/sec
map	433176.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark compares the performance of four different approaches to check if an element exists in an array:

1. `Array.find()`
2. `Array.indexOf()`
3. `Array.filter()` with a callback function that checks for existence
4. A simple `Map` data structure to store elements and their existence

**Options Compared**

The benchmark compares the performance of these four approaches in three ways:

* **Existence Check**: The time taken to check if an element exists in the array using each approach.
* **Frequency**: The number of times each approach is executed (i.e., how many iterations) for a fixed input.

**Pros and Cons of Each Approach**

1. **Array.find()**:
	* Pros: Efficient, as it only scans the array until it finds the element or reaches the end.
	* Cons: Can throw an error if the element is not found, and may have performance issues with large arrays.
2. **Array.indexOf()**:
	* Pros: Fast and accurate, but can be slower than `Array.find()` for very large arrays.
	* Cons: May return -1 instead of a falsey value if the element is not found.
3. **Array.filter() with a callback function**:
	* Pros: Flexible, as it allows filtering based on multiple conditions.
	* Cons: Slower than `Array.find()` and `Array.indexOf()`, especially for large arrays.
4. **Map**:
	* Pros: Fast and efficient, especially for large datasets.
	* Cons: Requires more memory to store the map data structure.

**Library and Purpose**

In this benchmark, the `Map` library is used to store elements as keys, which allows for fast existence checks using the `in` operator. The purpose of using a `Map` is to demonstrate its performance benefits in this specific use case.

**Special JS Features/Syntax**

None of the test cases explicitly uses special JavaScript features or syntax like async/await, generators, or decorators. However, it's worth noting that some of these approaches may be more suitable for certain scenarios where existence checks are used in conjunction with other operations.

**Other Alternatives**

If you're looking for alternative approaches to check if an element exists in an array, consider:

1. `Array.includes()`: A modern approach that is faster and more readable than `Array.indexOf()` or `Array.find()`.
2. Using a `Set` data structure instead of an array.
3. Using a caching mechanism like Redis or Memcached for large datasets.

Keep in mind that the choice of approach depends on the specific use case, performance requirements, and memory constraints.

Related benchmarks:

Array.find vs Array.indexOf vs Array.filter vs Map.has (version: 0)

Compare performance between Array.find vs Map.has

Comparing performance of: find vs indexOf vs filter vs map

Created: 10 months ago by: Guest

Jump to the latest result

find

indexOf

filter

map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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