Benchmark: Array.find vs. Map.get 20241610

Script Preparation code:

function getRandomElement(id) {
  return {
    id,
    a: Math.random(),
    b: Math.random(),
    c: Math.random(),
  }
}

function getArray(length) {
  const result = [];
  for (let i = 0; i < length; i++) {
    result.push(getRandomElement(i))
  }
  
  return result;
}

function arrayToMap(array) {
  return new Map(array.map(el => [el.id, el]));
}

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

array_small = getArray(10000);
array_large = getArray(1000000);

map_small = arrayToMap(array_small);
map_large = arrayToMap(array_large);

Tests:

Array.find, 10 000 elements
const target = getRandomInt(9999); for (let i = 0; i < 1000; i++) { array_small.find(el => el.id === target); }
Map.get, 10 000 elements
map_small = arrayToMap(array_small); for (let i = 0; i < 1000; i++) { const target = getRandomInt(9999); map_small.get(target); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.find, 10 000 elements
Map.get, 10 000 elements

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Linux

View result in a separate tab

Test name	Executions per second
Array.find, 10 000 elements	98.2 Ops/sec
Map.get, 10 000 elements	498.5 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided JSON represents a benchmark definition for comparing the performance of `Array.find` versus `Map.get` with various array sizes, as well as with/without conversion from array to map.

**Tested Options**

The benchmark compares two options:

1. **Array.find**: A method that searches for an element in an array based on a predicate function.
2. **Map.get**: A method that retrieves the value associated with a given key from a Map object.

**Pros and Cons of Each Approach**

*   **Array.find**:
    *   Pros: Simple, efficient, and widely supported by most JavaScript engines.
    *   Cons: Can be slower for very large arrays due to its iterative approach. It's also less memory-efficient than `Map.get` because it creates a new array of indices that match the desired element.
*   **Map.get**:
    *   Pros: More efficient and memory-friendly, especially for large datasets. It uses a hash table data structure under the hood, which provides faster lookup times.
    *   Cons: Less widely supported by older JavaScript engines, requires an additional Map object creation.

**Library Used**

In this benchmark, the `arrayToMap` function is used to create a Map object from an array. This library facilitates converting arrays to Maps for easier comparison of their performance with `Array.find`.

```javascript
function arrayToMap(array) {
    return new Map(array.map(el => [el.id, el]));
}
```

**Other Considerations**

*   The benchmark uses random element generation (`getRandomElement`) and array size variation (`getArray`) to ensure that the results are representative of real-world scenarios.
*   The `getRandomInt` function is used to generate random integers for testing purposes.

**Alternatives**

For a more comprehensive comparison, consider adding additional benchmarks for other operations, such as:

*   **Array.forEach**: Iterating over an array using `forEach`.
*   **Set.has**: Checking if an element exists in a Set object.
*   **DOM manipulation**: Performing DOM-related tasks, like traversing or searching elements.

By expanding the benchmark to cover more scenarios, you can gain a better understanding of how different JavaScript engines and libraries perform under various workloads.

Related benchmarks:

Array.find vs. Map.get 20241610 (version: 0)

Test the performance of Array.find vs. Map.get, with various array sizes, and with/without conversion from array to map

Comparing performance of: Array.find, 10 000 elements vs Map.get, 10 000 elements

Created: one year ago by: Guest

Jump to the latest result

Array.find, 10 000 elements

Map.get, 10 000 elements

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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