Benchmark: Filter v. Splice 2

Script Preparation code:

const item = {
    a: 'a',
    b: Math.floor(Math.random() * 4000),
    c: true,
    d: 'nice'
};

var items = new Array(10000).fill(item);

const toFind = {
    a: 'a',
    b: Math.floor(Math.random() * 4000),
    c: true,
    d: 'banana'
};

items.splice(4321, 0, toFind);

const itemsB = new Array(1000).fill('cool')
itemsB.splice(4321, 0, 'banana')

function removeFromArray(arr, item, by) {
    const index = by ?
        arr.findIndex((i) => i[by] === item[by]) :
        arr.indexOf(item);
    if (index > -1) {
        arr.splice(index, 1);
    }
    return arr;
}

function removeFromArrayByValue(x, value, by) {
    const arr = x ? [...x] : []
    const index = by ?
        arr.findIndex((i) => i[by] === value) :
        arr.indexOf(value);
    if (index > -1) {
        arr.splice(index, 1);
    }
    return arr;
}

Tests:

Filter
const x = [...items] x.filter((item) => item.d !== 'banana'); return x;
Splice
const y = [...items] y.splice(y.findIndex((item) => item.d === 'banana'), 1); return y;
Via Helper
const r = removeFromArrayByValue(items, 'banana', 'd') return r

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
Splice
Via Helper

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 a crucial aspect of developing fast and efficient web applications.

**Benchmark Overview**

The provided benchmark definition represents three test cases:

1.  **Filter**: This test case measures the time it takes to filter an array of objects using the `filter()` method. The array contains 10,000 objects with varying properties.
2.  **Splice**: This test case measures the time it takes to remove a specific object from an array using the `splice()` method. The array also contains 10,000 objects and is modified in-place.
3.  **Via Helper**: This test case uses a custom helper function, `removeFromArrayByValue()`, to achieve the same result as Splice.

**Options Compared**

The three test cases compare different approaches to achieve the same goal:

*   **Filter**: Uses the built-in `filter()` method to create a new array with filtered objects.
*   **Splice**: Modifies the original array in-place by removing a specific object using `splice()`.
*   **Via Helper**: Utilizes a custom helper function, `removeFromArrayByValue()`, which creates a copy of the original array and removes the desired element.

**Pros and Cons**

Here's a brief overview of each approach:

*   **Filter**:
    *   Pros: Efficient, does not modify the original array, and returns a new array.
    *   Cons: Creates a new array, can be slower for large arrays due to memory allocation.
*   **Splice**:
    *   Pros: Modifies the original array in-place, can be faster than filter for large arrays.
    *   Cons: Modifies the original array, can lead to unexpected side effects if not used carefully.
*   **Via Helper**:
    *   Pros: Similar to Splice but returns a new array instead of modifying the original one.
    *   Cons: Creates an additional copy of the array.

**Library Usage**

None of the test cases use any external libraries.

**Special JS Feature/Syntax**

The custom helper function, `removeFromArrayByValue()`, uses the spread operator (`...`) to create a copy of the array. This is a modern JavaScript feature introduced in ECMAScript 2015 (ES6).

**Other Considerations**

When choosing between these approaches, consider the following factors:

*   **Performance**: Filter and Splice have different performance characteristics. For large arrays, Splice can be faster due to its in-place modification. However, Filter returns a new array, which can lead to slower performance.
*   **Code Readability**: Filter is often considered more readable than Splice, as it clearly expresses the intent of creating a new array without modifying the original one.
*   **Memory Allocation**: Filter creates a new array and allocates memory for it. This can be costly for large arrays.

**Alternatives**

Some alternative approaches to filtering or removing elements from an array include:

*   Using `Array.prototype.reduce()`
*   Utilizing `Set` data structures
*   Employing `Array.prototype.every()` or `Array.prototype.some()` methods

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

It's worth noting that the current results might be skewed by the presence of repeated values (e.g., 'a', 'banana' etc.) which can cause performance degradation for certain browsers

Related benchmarks:

Filter v. Splice 2 (version: 0)

Comparing performance of: Filter vs Splice vs Via Helper

Created: 4 years ago by: Guest

Jump to the latest result

Filter

Splice

Via Helper

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):