Benchmark: for-in: cached vs non-cached 2

Script Preparation code:

class Second {
    dict = {}
    loopCached() {
        const dict = this.dict;
        for (const key in dict) {
            if (dict.hasOwnProperty(key)) {
                cb(dict[key], key);
            }
        }
    }
    loop() {
        for (const key in this.dict) {
            if (this.dict.hasOwnProperty(key)) {
                cb(this.dict[key], key);
            }
        }
    }
}

window.second = new Second();

for (let i = 0; i < 1e6; i++) {
    second["dict"][i] = i
}

const cb = (k, v) => {
    return v % 2
}

Tests:

Non Cached
second.loop()
Cached
second.loopCached()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Non Cached
Cached

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.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmarking test case on the MeasureThat.net website. The benchmark compares the performance of two approaches: `loopCached()` and `loop()`. Both functions are part of an object named `dict` in an instance of a class named `Second`.

**Script Preparation Code**

The script preparation code defines a class named `Second` with two methods:

1. `loop()`: Iterates over the keys in the `dict` object using a traditional `for-in` loop.
2. `loopCached()`: Iterates over the keys in the `dict` object using a cached reference to the object, which is assigned to the variable `dict`.

The script also creates an instance of the `Second` class and populates the `dict` object with 1 million key-value pairs.

**Html Preparation Code**

There is no HTML preparation code provided, which means that this benchmark only tests the JavaScript engine's performance and does not involve any DOM-related operations or events.

**Options Compared**

The two options compared in this benchmark are:

1. **Cached iteration**: The `loopCached()` method uses a cached reference to the object, which is assigned to the variable `dict`. This approach avoids re-creating the object reference on each iteration.
2. **Non-cached iteration**: The `loop()` method iterates over the keys in the `dict` object using a traditional `for-in` loop.

**Pros and Cons**

1. **Cached iteration (loopCached())**:
	* Pros: Reduced overhead of re-creating object references, potentially faster performance.
	* Cons: May lead to slower initial iterations due to caching initialization.
2. **Non-cached iteration (loop())**:
	* Pros: No potential for slower initial iterations due to caching initialization.
	* Cons: More overhead from re-creating object references on each iteration.

**Library and Purpose**

There is no explicit library mentioned in the provided code, but it appears to be a self-contained JavaScript class. The `dict` object is likely an example of a simple data structure used for benchmarking purposes.

**Special JS Features or Syntax**

The benchmark does not appear to utilize any special JavaScript features or syntax beyond what is commonly available in modern browsers.

**Other Considerations**

* **Optimization**: The benchmark may be optimized for specific use cases, such as web development or performance-critical applications.
* **Browser Variations**: MeasureThat.net tests are often run on multiple browser versions and platforms to ensure cross-browser compatibility. This might affect the results of this particular benchmark.

**Alternatives**

If you want to test similar JavaScript microbenchmarks, consider exploring other resources, such as:

1. jsPerf: A popular online tool for comparing the performance of different JavaScript implementations.
2. Benchmark.js: A lightweight library for creating and running benchmarks in Node.js.
3. Google's Benchmarking Guidelines: A set of guidelines for writing efficient and well-documented benchmarking code.

Keep in mind that each benchmarking platform or tool may have its own strengths, weaknesses, and specific use cases, so it's essential to choose the right tool for your testing needs.

Related benchmarks:

for-in: cached vs non-cached 2 (version: 0)

Comparing performance of: Non Cached vs Cached

Created: 3 years ago by: Guest

Jump to the latest result

Non Cached

Cached

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):