Benchmark: Map constructor and setter

Script Preparation code:

var arr = [
  { a: 'Ghkfj', b: 'Yvtzq', c: 'Rwsde' },
  { a: 'Bpqwm', b: 'Sdfgh', c: 'Zxcvb' },
  { a: 'Olmnp', b: 'Iujkl', c: 'Qwerty' },
  { a: 'Cdsaf', b: 'Asdfg', c: 'Xcvbn' },
  { a: 'Qwerz', b: 'Cvbnm', c: 'Xcvbn' }
]

Tests:

Map setting
const map = new Map() arr.forEach(el => map.set(el.a, el))
Map constructor
const map = new Map(arr.map(el => [el.a, el]))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map setting
Map constructor

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36

Browser/OS: Chrome 136 on Windows

View result in a separate tab

Test name	Executions per second
Map setting	9317032.0 Ops/sec
Map constructor	6575226.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is tested, compared, and analyzed in the benchmark.

**Benchmark Definition**

The benchmark measures the performance of two approaches to working with Maps in JavaScript:

1. **Map constructor**: This approach creates a new Map object and then sets key-value pairs using the `set()` method.
2. **Map setting**: This approach directly iterates over an array and sets key-value pairs on a newly created Map object.

**Options Compared**

The benchmark compares two approaches, each with its pros and cons:

1. **Map constructor**
	* Pros:
		+ Creates a new Map object upfront, which can improve performance for large datasets.
		+ Can be more explicit and readable.
	* Cons:
		+ May incur overhead due to creating a new object.
2. **Map setting**
	* Pros:
		+ Iterates over the array in a single step, reducing memory allocation and deallocation.
		+ Can be faster for small datasets or when iteration is cheap.
	* Cons:
		+ Requires iterating over the array, which can be slower than creating a new Map object upfront.

**Library/Functionality**

There is no specific library used in this benchmark. However, JavaScript's built-in `Map` object and array methods (`forEach()` and `map()`) are utilized.

**Special JS feature/Syntax**

The benchmark uses some advanced features of JavaScript, including:

1. **Arrow functions**: The `arr.forEach(el => map.set(el.a, el))` expression uses an arrow function to define a small, anonymous function.
2. **Template literals**: The `var arr = [\r\n ... \r\n];` and `"const map = new Map()\narr.forEach(el => map.set(el.a, el));"` expressions use template literals to create multiline strings.

**Other Alternatives**

Alternative approaches could include:

1. Using the `Array.reduce()` method instead of `forEach()`: This would create a new Map object upfront, similar to the map constructor approach.
2. Using a library like Lodash or Ramda, which provides utility functions for working with Maps and arrays.
3. Using a different data structure, such as an object or a Set, if the performance characteristics are significantly different.

Keep in mind that these alternatives may not be directly comparable to the original benchmarking approach, and their performance may vary depending on specific use cases and environments.

Related benchmarks:

Map constructor and setter (version: 0)

perfomance with adding elements

Comparing performance of: Map setting vs Map constructor

Created: one year ago by: Guest

Jump to the latest result

Map setting

Map constructor

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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