Benchmark: Array.includes() vs Set.has()

Array.includes() vs Set.has() (version: 0)

Comparing performance of: Array.includes, 10 000 elements vs Array.includes, 1 000 000 elements vs Set.has, 10 000 elements vs Set.has, 1 000 000 elements vs Array to Set + Set.has, 10 000 elements vs Array to Set + Set.has x 100, 10 000 elements vs Array.includes x 100, 10 000 elements

Created: 3 years ago by: Registered User

Jump to the latest result

Script Preparation code:

function getArray(length) {
  const result = [];
  for (let i = 0; i < length; i++) {
    result.push(i + 'abc'); // In case the browser does some sort of optimization for arrays with only integers ¯\_(ツ)_/¯
  }
  return result;
}

function getRandomTargetElement(arrayLength) {
  const index = Math.floor(Math.random() * arrayLength);
  return index + 'abc';
}


array_small = getArray(10000);
array_large = getArray(1000000);

set_small = new Set(array_small);
set_large = new Set(array_large);

Tests:

Array.includes, 10 000 elements
array_small.includes(getRandomTargetElement(10000));
Array.includes, 1 000 000 elements
array_large.includes(getRandomTargetElement(1000000))
Set.has, 10 000 elements
set_small.has(getRandomTargetElement(10000))
Set.has, 1 000 000 elements
set_large.has(getRandomTargetElement(1000000))
Array to Set + Set.has, 10 000 elements
const target = getRandomTargetElement(10000); const set = new Set(array_small); set.has(target)
Array to Set + Set.has x 100, 10 000 elements
const set = new Set(array_small); for (let i = 0; i < 100; i++) { const target = getRandomTargetElement(10000); set.has(target) }
Array.includes x 100, 10 000 elements
for (let i = 0; i < 100; i++) { const target = getRandomTargetElement(10000); array_small.includes(target) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes, 10 000 elements
Array.includes, 1 000 000 elements
Set.has, 10 000 elements
Set.has, 1 000 000 elements
Array to Set + Set.has, 10 000 elements
Array to Set + Set.has x 100, 10 000 elements
Array.includes x 100, 10 000 elements

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.0

Browser/OS: Firefox 151 on Linux

View result in a separate tab

Test name	Executions per second
Array.includes, 10 000 elements	58100.5 Ops/sec
Array.includes, 1 000 000 elements	546.7 Ops/sec
Set.has, 10 000 elements	71376128.0 Ops/sec
Set.has, 1 000 000 elements	60950632.0 Ops/sec
Array to Set + Set.has, 10 000 elements	1387.1 Ops/sec
Array to Set + Set.has x 100, 10 000 elements	1377.3 Ops/sec
Array.includes x 100, 10 000 elements	572.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Overview**

The benchmark measures the performance difference between `array.includes()` and `set.has()` operations on large arrays and sets.

**Options Compared**

Two options are compared:

1. **Array.includes()**: A method that checks if a specified value exists in an array.
2. **Set.has()**: A method that checks if a specified value exists in a set (a collection of unique values).

**Pros and Cons of Each Approach:**

*   **Array.includes():**
    *   Pros:
        *   Wide support across browsers and Node.js versions
        *   Can be used for more complex data structures, such as arrays with duplicate values
    *   Cons:
        *   May perform slower on large datasets due to the need to iterate over the array
*   **Set.has():**
    *   Pros:
        *   Generally faster than `array.includes()` for large datasets
        *   Can be more memory-efficient since sets only store unique values
    *   Cons:
        *   Less support across browsers and Node.js versions (specifically, older browsers and some older Node.js versions may not support sets)
        *   May require more complex code to convert data structures to sets

**Other Considerations:**

*   **Preparation Code:** The benchmark preparation code creates large arrays and sets using the `getArray()` function. This ensures consistent input data for each test case.
*   **Random Targets:** The `getRandomTargetElement()` function generates random targets for the includes() and has() operations, reducing any potential optimizations that might favor specific values.

**Library Use:**

The benchmark uses the `Set` object to represent sets. The `Set` class is a built-in JavaScript object that provides an efficient way to store unique values.

**Special JS Features/Syntax (None Mentioned):**

No special JavaScript features or syntax are used in this benchmark.

**Alternatives:**

If you're interested in exploring other benchmarking tools, consider the following alternatives:

*   **Benchmark.js:** A popular benchmarking library for Node.js that provides a simple and efficient way to measure performance.
*   **WebPageTest:** A web testing tool that also offers benchmarking capabilities for measuring page load times and performance.
*   **Benchmark Library (in browser):** Built-in Benchmark Library in browsers like Chrome, Firefox and others

Related benchmarks: