Benchmark: update Element in a array

Script Preparation code:

var oldData = Array.from({
    length: 1000000
}, (_, index) => ({
    id: index + 1,
    name: `name_${index+1}`
}));

var row = {
    id: 532
}

function sliceMethod(oldData, row){
    const index = oldData.findIndex(
        item => item.id === row.id
    );
    return {
        queues: {
            data: [
                ...oldData.slice(0, index),
                {
                    ...oldData[index],
                    active: true,
                    version: String(
                        +oldData[index].version + 1
                    )
                },
                ...oldData.slice(index + 1)
            ]
        }
    };
}

function mapMethod(oldData, row){
    const data = oldData.map(item => {
        if (item.id !== row.id) return item
        return {
            ...item,
            active: true,
            version: String(+item.version + 1)
        };
    })
    return {
        queues: {
            data
        }
    };
}

Tests:

Map Method
mapMethod(oldData, row);
Slice Method
sliceMethod(oldData,row);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map Method
Slice Method

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.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition JSON**

The benchmark definition is a JSON object that defines two test cases: "Map Method" and "Slice Method". The script preparation code for each test case is provided, along with an optional HTML preparation code (which is empty in this case).

The script preparation code creates an array of 1 million objects, `oldData`, which will be used as input for the test cases. Each object in the array has two properties: `id` and `name`.

**Test Cases**

There are two test cases:

1. **Map Method**: This test case uses the `map()` method to update each object in `oldData`. The function `sliceMethod` is not used in this test case.
2. **Slice Method**: This test case uses the `slice()` method to update a subset of objects in `oldData`. Specifically, it finds the index of the object with `id = 532`, slices the array up to that index, updates the original object at that index by adding an `active` property and incrementing its `version` property, and then slices the array again to exclude the updated object. The function `mapMethod` is not used in this test case.

**Options Compared**

The two test cases compare the performance of different approaches:

1. **Map Method**: This approach uses the `map()` method, which creates a new array with the transformed elements.
2. **Slice Method**: This approach uses the `slice()` method to create a subset of the original array and updates individual objects within that subset.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Map Method**
	* Pros: Creates a new array, which can be more predictable and efficient for certain use cases.
	* Cons: Creates a new array, which can lead to memory allocation overhead.
2. **Slice Method**
	* Pros: Updates individual objects in the original array, which can be more memory-efficient than creating a new array.
	* Cons: Requires finding the index of the target object, which can lead to additional overhead.

**Library**

There is no explicit library mentioned in the benchmark definition. However, the `findIndex()` method used in the `sliceMethod` function is part of the ECMAScript standard.

**Special JS Feature or Syntax**

The benchmark definition does not use any special JavaScript features or syntax that are not widely supported by modern browsers.

**Other Alternatives**

There may be other approaches to updating an array, such as using a loop or recursion. However, these alternatives are likely to have similar performance characteristics to the Map and Slice methods used in this benchmark.

In summary, this benchmark tests the performance of two different approaches: creating a new array with `map()` versus updating individual objects within the original array using `slice()`. The results will provide insight into which approach is faster and more memory-efficient for large datasets.

Related benchmarks:

update Element in a array (version: 0)

Comparing performance of: Map Method vs Slice Method

Created: 2 years ago by: Guest

Jump to the latest result

Map Method

Slice Method

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):