Benchmark: toMap - iterative vs .map

Script Preparation code:

var values = Array(100).fill(0).map((v, idx) => [idx.toString(), idx]);

function toMapMap(
    array,//: T[],
    keyFn,//: (value: T) => K,
    valueFn,//: (value: T) => V
) {
    return new Map(array.map((value) => [keyFn(value), valueFn(value)]));
}


function toMapIterative(
    array,//: T[],
    keyFn,//: (value: T) => K,
    valueFn,//: (value: T) => V
) {
    const m = new Map();
  	for (let i = 0; i < array.length; i++) {
      const value = array[i];
      m.set(keyFn(value), valueFn(value));
    }
    return m;
}

Tests:

toMapMap
toMapMap(values, v => v[0], v => v[1])
toMapIterative
toMapIterative(values, v => v[0], v => v[1])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toMapMap
toMapIterative

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition JSON**

The provided benchmark definition is a JSON object that defines two JavaScript functions, `toMapMap` and `toMapIterative`. These functions are designed to convert an array of values into a Map data structure. The difference between the two functions lies in their implementation:

*   `toMapMap`: This function uses the `.map()` method to create a new array with transformed key-value pairs, which is then used to create a new Map object.
*   `toMapIterative`: This function iterates over the input array manually using a for loop and sets each value in the resulting Map object.

**Options Compared**

The benchmark compares the performance of these two approaches:

1.  **`.map()` method**: This is a built-in JavaScript method that returns a new array with transformed elements.
2.  **Manual iteration**: This approach uses a traditional for loop to iterate over the input array and set values in the resulting Map object.

**Pros and Cons**

Here are some pros and cons of each approach:

*   `.map()` method:
    *   Pros:
        *   Concise and readable code.
        *   Built-in function, so it's well-optimized by JavaScript engines.
    *   Cons:
        *   May incur overhead due to the creation of an intermediate array.
        *   Less control over iteration and mapping.
*   Manual iteration:
    *   Pros:
        *   More control over iteration and mapping.
        *   Can be more efficient if the input data is large or has complex formatting requirements.
    *   Cons:
        *   Requires more code and understanding of loop variables.
        *   Less readable and maintainable.

**Libraries and Special Features**

None of the test cases use any external libraries. However, it's worth noting that JavaScript engines may have built-in optimizations or features that can affect performance, such as:

*   Just-In-Time (JIT) compilation: Some browsers, like Chrome, have JIT compilers that can optimize code at runtime.
*   Garbage collection: Most modern JavaScript engines use a garbage collector to manage memory and reduce pauses.

**Test Cases**

The provided test cases are simple examples of how to create and run benchmarks using MeasureThat.net. The `toMapIterative` function is expected to outperform the `.map()` method approach due to its more direct and controlled iteration process.

To prepare these benchmark tests, you would need to:

1.  Define a clear objective for your test case (e.g., comparing performance of two approaches).
2.  Write code that implements both approaches.
3.  Use MeasureThat.net to create and run the benchmarks with desired input data.
4.  Analyze the results to determine which approach is more efficient.

**Alternatives**

If you're looking for alternative benchmarking tools or methods, here are some options:

*   **Benchmarking frameworks**: Tools like Benchmark.js or Fastbench provide structured approaches to benchmarking JavaScript code.
*   **Browser-specific benchmarks**: Some browsers, like V8 (used by Chrome), have their own benchmarking tools and guidelines.
*   **CPU-focused benchmarks**: For CPU-intensive tasks, consider using benchmarks specifically designed for that purpose, such as those provided by Intel's Performance Tuning Guide.

By following these steps and using the right tools, you can create high-quality benchmarks to compare performance and optimize your JavaScript code.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Linux

View result in a separate tab

Test name	Executions per second
toMapMap	237678.3 Ops/sec
toMapIterative	326638.8 Ops/sec

Related benchmarks:

toMap - iterative vs .map (version: 0)

Comparing performance of: toMapMap vs toMapIterative

Created: one year ago by: Guest

Jump to the latest result

toMapMap

toMapIterative

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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