Benchmark: Object.values vs for in loop vs for loop v2 borys

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Tests:

mapValues (every item uniq)
const obj = []; for (let i = 0; i <= 10000; i++) { obj.push({ id: i }); }; const mapValues = () => { const inputs = Object.values(obj).map(r => r.id); const hasMulti = _.uniq(inputs).length > 1; return hasMulti; } mapValues();
for loop (every item uniq)
const obj = []; for (let i = 0; i <= 10000; i++) { obj.push({ id: i }); }; const mapFor = () => { var m = new Map(); var values = Object.values(obj); for (let i = 0; i < values.length; i++) { var id = values[i].id; m.set(id, 0); if (m.size > 1) { return true; } }; return false; }; mapFor();
mapValues (all items same)
const obj = []; for (let i = 0; i <= 10000; i++) { obj.push({ id: 1 }); }; const mapValues = () => { const inputs = Object.values(obj).map(r => r.id); const hasMulti = _.uniq(inputs).length > 1; return hasMulti; } mapValues();
for loop (all items same)
const obj = []; for (let i = 0; i <= 10000; i++) { obj.push({ id: 1 }); }; const mapFor = () => { var m = new Map(); var values = Object.values(obj); for (let i = 0; i < values.length; i++) { var id = values[i].id; m.set(id, 0); if (m.size > 1) { return true; } }; return false; }; mapFor();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
mapValues (every item uniq)
for loop (every item uniq)
mapValues (all items same)
for loop (all items same)

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll dive into explaining the benchmark.

**Overview**

The provided JSON represents a JavaScript microbenchmarking test case, which compares the performance of three different approaches: using `Object.values()` with the `map` function (`mapValues`), a traditional `for` loop with an array (`for loop (every item uniq)`), and another traditional `for` loop with an array, but with all items having the same value (`for loop (all items same)`). The test also uses the Lodash library.

**Options Compared**

The benchmark compares the following options:

1. **`mapValues`**: Uses `Object.values()` to get an array of values from an object and then maps over it using the `map` function to count the number of unique elements.
2. **Traditional `for` loop (every item uniq)**: Iterates over the array created by `Object.values()` using a traditional `for` loop, checks if each element is unique, and returns true if more than one element is unique.
3. **Traditional `for` loop (all items same)**: Similar to the previous option, but with all elements having the same value.

**Pros and Cons**

*   **`mapValues`**: Pros:
    *   Simple and concise code.
    *   Uses modern JavaScript features.
Cons:
    *   May have performance overhead due to the use of `map()` and `uniq()`.
*   Traditional `for` loop (every item uniq): Pros:
    *   Avoids potential overhead of modern JavaScript features.
Cons:
    *   More verbose code.
    *   Less readable for complex logic.
*   Traditional `for` loop (all items same): Similar pros and cons as the previous option.

**Lodash Library**

The Lodash library is used to implement the `uniq()` function, which returns an array with unique elements. The `mapValues` test case uses this function to count the number of unique elements in the array created by `Object.values()`. While using a third-party library can provide convenience and efficiency, it also introduces dependencies that might affect performance.

**Other Considerations**

*   **Data Structure**: The benchmark uses an object with 10,000 properties to create an array of values. This data structure may not be representative of real-world scenarios, where objects are often used for more complex data structures.
*   **Performance**: The benchmark measures the execution time per second for each test case on a desktop device running Chrome 104. The results indicate that `mapValues` outperforms the traditional `for` loops in this specific scenario.

**Alternatives**

If you were to reimplement these benchmarks without using Lodash, you could:

1.  Use the native JavaScript methods `Set` or `Map` instead of `uniq()` to count unique elements.
2.  Implement the `mapValues` logic from scratch using simple array operations.
3.  Consider using a different data structure, such as an array with unique values, to eliminate the need for the traditional `for` loops.

Ultimately, the choice of approach depends on your specific requirements and performance constraints.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.36

Browser/OS: Chrome 104 on Windows

View result in a separate tab

Test name	Executions per second
mapValues (every item uniq)	1012.8 Ops/sec
for loop (every item uniq)	7198.1 Ops/sec
mapValues (all items same)	1859.9 Ops/sec
for loop (all items same)	2763.1 Ops/sec

Related benchmarks:

Object.values vs for in loop vs for loop v2 borys (version: 0)

Comparing performance of: mapValues (every item uniq) vs for loop (every item uniq) vs mapValues (all items same) vs for loop (all items same)

Created: 2 years ago by: Guest

Jump to the latest result

mapValues (every item uniq)

for loop (every item uniq)

mapValues (all items same)

for loop (all items same)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):