Benchmark: ES6 Map Merge vs forEach

Script Preparation code:

const entries1 = [];
const entries2 = [];
for (let i = 0; i < 1000; i++) {
  entries1[i] = [i , i];
}
for (let i = 0; i < 1000; i++) {
  entries2[i] = [i + 500, i + 600];
}
const pathSegmentMap = new Map(entries1);
const newSegmentMap = new Map(entries2);

Tests:

Merge
const entries1 = []; const entries2 = []; for (let i = 0; i < 1000; i++) { entries1[i] = [i , i]; } for (let i = 0; i < 1000; i++) { entries2[i] = [i + 500, i + 600]; } const pathSegmentMap = new Map(entries1); const newSegmentMap = new Map(entries2); const mergeMap = new Map([...pathSegmentMap, ...newSegmentMap]);
Loop
const entries1 = []; const entries2 = []; for (let i = 0; i < 1000; i++) { entries1[i] = [i , i]; } for (let i = 0; i < 1000; i++) { entries2[i] = [i + 500, i + 600]; } const pathSegmentMap = new Map(entries1); const newSegmentMap = new Map(entries2); newSegmentMap.forEach((value, key) => { pathSegmentMap.set(key, value); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Merge
Loop

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/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Merge	10202.1 Ops/sec
Loop	16275.6 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 benchmark definition and test cases to understand what's being tested.

**Benchmark Definition**

The benchmark is defined in JSON format, which contains information about the test case:

* `Name`: The name of the benchmark, "ES6 Map Merge vs forEach".
* `Description`: An empty string, indicating that no description is provided.
* `Script Preparation Code`: A JavaScript code snippet that creates two arrays, `entries1` and `entries2`, each with 1000 elements. The arrays are populated with nested arrays containing two values each.
* `Html Preparation Code`: An empty string, indicating that no HTML preparation is required.

**Test Cases**

There are two test cases:

1. **Merge**:
	* `Benchmark Definition`: A JavaScript code snippet that creates a new map by merging two existing maps, `pathSegmentMap` and `newSegmentMap`, using the spread operator (`...`).
2. **Loop**:
	* `Benchmark Definition`: A JavaScript code snippet that iterates over the elements of `newSegmentMap` and updates the values in `pathSegmentMap` using a loop.

**What's being tested**

The benchmark is testing the performance difference between two approaches:

1. **Merge**: Using the spread operator to merge two maps.
2. **Loop**: Iterating over the elements of one map and updating another map using a loop.

**Pros and Cons**

* **Merge**:
	+ Pros:
		- Concise and readable syntax.
		- Efficient, as it avoids the need for explicit looping.
	+ Cons:
		- May have performance overhead due to the use of the spread operator.
		- Can be slower than manual iteration in some cases (e.g., when dealing with large datasets).
* **Loop**:
	+ Pros:
		- Can be faster, as it avoids the overhead of the spread operator.
		- Can be more controlled and predictable.
	+ Cons:
		- More verbose syntax can make the code harder to read.
		- Requires explicit looping, which can lead to errors if not done correctly.

**Libraries**

The benchmark uses JavaScript's built-in `Map` data structure, which is a dictionary-like object that stores key-value pairs. No external libraries are required for this benchmark.

**Special JS features/syntax**

The benchmark does not use any special JavaScript features or syntax. It only relies on standard JavaScript constructs and methods.

**Alternatives**

Other alternatives to test the performance of merging maps include:

* Using `Object.assign()` instead of the spread operator.
* Using a library like Lodash's `merge` function.
* Testing with manual iteration using a `for...in` loop or a `forEach` loop (similar to the "Loop" test case).

Keep in mind that the choice of approach depends on the specific requirements and constraints of the project.

Related benchmarks:

ES6 Map Merge vs forEach (version: 0)

Comparing performance of: Merge vs Loop

Created: 6 years ago by: Guest

Jump to the latest result

Merge

Loop

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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