Benchmark: non-unique-elements

Tests:

Count
for(var i=0;i<10000;i++) { var data = [1, 2, 3, 1, 3]; var cnt = {}; data.forEach(d => cnt[d] ? cnt[d]++ : cnt[d]=1); data.filter(d => cnt[d] > 1); }
IndexOf
for(var i=0;i<10000;i++) { var data = [1, 2, 3, 1, 3]; data.filter(d => data.indexOf(d) != data.lastIndexOf(d)); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Count
IndexOf

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is crucial for optimizing code and ensuring it runs efficiently across different browsers and devices.

**Benchmark Definition**
The provided JSON represents the benchmark definition, which includes:

*   **Script Preparation Code**: The script preparation code is empty in this case, meaning that no specific setup or initialization code needs to be executed before running the benchmarks.
*   **Html Preparation Code**: The HTML preparation code is also empty, indicating that no special HTML setup is required for these benchmarks.

**Options Compared**
In these benchmarks, two different approaches are compared:

1.  **Counting with Object**: In the "Count" test case, an object (`cnt`) is used to count the occurrences of each element in the `data` array.
2.  **IndexOf Method**: The second benchmark uses the `indexOf()` method to compare the indices of consecutive occurrences of elements in the `data` array.

**Pros and Cons**

*   **Counting with Object**:
    *   **Advantages**:
        *   More efficient for arrays with duplicate elements, as it only increments the count once per occurrence.
        *   Allows for easy handling of non-numeric values or NaNs (Not a Number) using the object's property name as the key.
    *   **Disadvantages**:
        *   Requires more memory to store the object and its properties.
        *   May have slower startup times due to the initial object creation.
*   **IndexOf Method**:
    *   **Advantages**:
        *   Simplifies the code, making it easier to read and maintain.
        *   Does not require additional memory or computations for duplicate elements.
    *   **Disadvantages**:
        *   Slower than the object approach for large arrays with many duplicates due to repeated function calls and comparisons.

**Library Usage**
There is no explicit library usage in these benchmarks. However, it's worth noting that JavaScript's built-in methods like `forEach`, `filter`, and `indexOf` are generally considered efficient and do not require additional libraries unless there are specific requirements or optimizations needed.

**Special JS Features or Syntax**
No special JavaScript features or syntax are used in these benchmarks. The code adheres to standard JavaScript syntax and practices.

**Other Alternatives**

*   **Other Counting Methods**: Alternative counting methods like using the `Set` object, an array of unique values, or even manual looping could be considered for performance optimizations.
*   **IndexOf Method Variants**: The `indexOf()` method can have variations like using a binary search algorithm or leveraging hardware acceleration (if supported by the browser and device).

Related benchmarks:

non-unique-elements (version: 0)

Comparing performance of: Count vs IndexOf

Created: 9 years ago by: Guest

Jump to the latest result

Count

IndexOf

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):