Benchmark: test map array and object perf

Script Preparation code:

var map = new Map();
var arr = [];
var obj = {};

var randomU32 = function() {
	return Math.random() * (1 << 31) >>> 0;
}

Tests:

map
map.set(randomU32(), true);
arr
arr[randomU32()] = true;
obj
obj[randomU32()] = true;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
arr
obj

Fastest: N/A

Slowest: N/A

Latest run results:

No previous 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 dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The benchmark is testing three different data structures: `Map`, `Array`, and `Object`. Each test case is designed to measure the performance of setting a value in each data structure.

**Options compared**

The options being compared are:

1. **`Map.set()`**: Testing the performance of setting a value using a `Map` data structure.
2. **`Array[index] = true`**: Testing the performance of setting a value using an array.
3. **`Object[key] = true`**: Testing the performance of setting a value using an object.

**Pros and Cons**

Here's a brief overview of each approach:

1. **`Map.set()`**:
	* Pros: Maps are designed for fast key-value lookups, making them suitable for this benchmark.
	* Cons: Using `set()` can be slower than direct assignment due to the overhead of checking if the key exists and updating the map.
2. **`Array[index] = true`**:
	* Pros: Arrays are optimized for random access and direct assignment is relatively fast.
	* Cons: Array indices start at 0, which might lead to slower performance when using arbitrary values like `Math.random() * (1 << 31)`.
3. **`Object[key] = true`**:
	* Pros: Objects are designed for storing key-value pairs, making them suitable for this benchmark.
	* Cons: Using `[]` syntax can be slower than direct assignment due to the overhead of creating an object.

**Other considerations**

In addition to the data structure itself, the benchmark also considers the following factors:

* **JavaScript engine**: The benchmark is run on Chrome 67, which might have optimized performance for these specific operations.
* **Platform and OS**: The benchmark is run on Windows 7, which could impact performance due to hardware or software limitations.

**Library usage**

There doesn't appear to be any external libraries used in the benchmark. However, the `Math.random()` function is a built-in JavaScript function that generates random numbers.

**Special JS features or syntax**

None are mentioned, but using arbitrary values like `Math.random() * (1 << 31)` can affect performance due to the overhead of generating random numbers.

Now, let's talk about alternatives!

Other data structures and methods you could use for this benchmark include:

* **`Set()`**: Similar to `Map.set()`, but optimized for adding unique values.
* **`SparseArray`**: A specialized array that uses sparse arrays to store only non-zero elements.
* **`WeakMap`**: A map that stores weak references, which can be useful in specific use cases.

Keep in mind that each data structure and method has its own strengths and weaknesses, and the best choice depends on your specific use case.

Related benchmarks:

test map array and object perf (version: 0)

Comparing performance of: map vs arr vs obj

Created: 7 years ago by: Guest

Jump to the latest result

map

arr

obj

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):