Benchmark: Map iteration vs Map.values() iteration

Script Preparation code:

var obj = {
  a: 1,
  b: 2,
  c: 3,
  d: 4,
  e: 5,
  f: 6,
  g: 7,
  h: 8,
  i: 9,
  j: 10,
  k: 11,
  l: 12,
  m: 13,
  n: 14,
  o: 15,
  p: 16,
  q: 17,
  r: 18,
  s: 19,
  t: 20,
  u: 21,
  v: 22,
  w: 23,
  x: 24,
  y: 25,
  z: 26
};
var map = new Map(Object.entries(obj));

Tests:

Map - for of kv
let total = 0; for (const [key, value] of map) { total += value; }
Map - for of map.values()
let total = 0; for (const value of map.values()) { total += value; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map - for of kv
Map - for of map.values()

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Map - for of kv	6076735.5 Ops/sec
Map - for of map.values()	12097248.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition**

The provided JSON defines two benchmark test cases: `Map iteration vs Map.values() iteration`. The script preparation code creates an object (`obj`) with 26 properties and converts it to a `Map` object using `Object.entries()`. This map is then used as the input for both benchmark test cases.

**Benchmark Test Cases**

There are two individual test cases:

1. **Map - for of kv**: This test case uses a traditional `for...of` loop to iterate over the key-value pairs of the map.
2. **Map - for of map.values()**: This test case uses the `map.values()` method to get an iterator over the values of the map, and then iterates over it using another `for...of` loop.

**Options Compared**

The two options being compared are:

* Traditional iteration using `for...of` loop on key-value pairs (test case 1)
* Iteration using `map.values()` method followed by a traditional `for...of` loop (test case 2)

**Pros and Cons of Each Approach**

* **Traditional Iteration**: This approach is straightforward and easy to understand. However, it may be slower than the alternative approach due to the overhead of iterating over key-value pairs.
	+ Pros: Easy to understand, no additional library or syntax required
	+ Cons: May be slower, more memory usage due to creating an iterator object
* **Map.values() Iteration**: This approach is optimized for performance and uses a built-in method to iterate over the values of the map. However, it may require understanding the internal implementation of `map.values()`.
	+ Pros: Optimized for performance, reduces memory usage compared to traditional iteration
	+ Cons: Requires understanding of `map.values()` internal implementation, may be less intuitive than traditional iteration

**Library and Its Purpose**

In both test cases, the `Map` object is used as a data structure. The `Map` class is a built-in JavaScript object that stores key-value pairs in a hash table.

**Special JS Features or Syntax**

There are no special JS features or syntax being used in these benchmark test cases. They only utilize standard JavaScript constructs and built-in methods.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are some examples:

* Using `for...in` loop to iterate over key-value pairs
* Using a traditional `forEach()` method with an iterator object
* Using WebAssembly (WASM) or other low-level optimization techniques

Keep in mind that these alternatives may require more expertise and may not be as efficient as the built-in methods used in MeasureThat.net.

I hope this explanation helps!

Related benchmarks:

Map iteration vs Map.values() iteration (version: 0)

Comparing performance of: Map - for of kv vs Map - for of map.values()

Created: one year ago by: Guest

Jump to the latest result

Map - for of kv

Map - for of map.values()

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):