Benchmark: Array vs. object large

Script Preparation code:

function createLargeArray() {
    return new Array(1000).fill(undefined).map((_, i) => i);
}

function createLargeObject() {
    return createLargeArray().reduce((acc, val) => {
        acc[val] = val % 2 ? true : false;
        return acc
    }, {})
}



var obj = createLargeObject();
var arr = createLargeArray();

Tests:

Object lookup
obj[500] !== undefined
Array lookup
arr.includes(500)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object lookup
Array lookup

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.

**Benchmark Explanation**

The provided benchmark measures the performance of JavaScript in two different data structures: arrays and objects.

The script preparation code defines two functions, `createLargeArray` and `createLargeObject`, which create large arrays and objects, respectively. The arrays are filled with 1000 elements using the `fill` method and mapped to generate unique values. The objects are created by reducing the array using the `reduce` method.

The HTML preparation code is empty, suggesting that the benchmark does not require any specific HTML structure or content.

**Comparison of Approaches**

There are two main approaches being compared:

1. **Array Lookup (`arr.includes(500)`)**: This approach uses the `includes` method to search for an element in the array.
2. **Object Lookup (`obj[500] !== undefined`)**: This approach uses direct property access to retrieve a value from the object.

**Pros and Cons of Each Approach**

1. **Array Lookup (`arr.includes(500)`)**:
	* Pros:
		+ Efficient use of memory, as arrays only allocate space for the elements they contain.
		+ Fast lookup performance, especially for large arrays, since it uses a binary search algorithm under the hood.
	* Cons:
		+ Requires the element to be present in the array, which might not always be the case.
2. **Object Lookup (`obj[500] !== undefined`)**:
	* Pros:
		+ Allows for more flexible searching, as any property can be accessed directly.
		+ Does not require the element to be present in the object (although it is checked).
	* Cons:
		+ Memory-intensive, as objects allocate space for each property.
		+ Can be slower than array lookup for large objects due to the overhead of property access.

**Library and Special JS Features**

No external libraries are used in this benchmark. However, some JavaScript features are employed:

1. **`fill` method**: Used to fill arrays with a specific value.
2. **`map` method**: Used to transform elements in an array.
3. **`reduce` method**: Used to reduce an array to a single value using a callback function.
4. **`includes` method**: Used to search for an element in an array (available in modern browsers and Node.js).
5. **Direct property access (`obj[500] !== undefined`)**: Used to retrieve values from objects.

**Other Alternatives**

For similar benchmarks, you can consider testing other data structures like:

1. **Linked lists**: For searching and inserting elements.
2. **Tries**: For fast string matching and prefix searches.
3. **Hash tables**: For fast key-value lookup and insertion.

Keep in mind that the choice of data structure and benchmark approach depends on the specific requirements and goals of your testing scenario.

Related benchmarks:

Array vs. object large (version: 0)

Comparing performance of: Object lookup vs Array lookup

Created: 3 years ago by: Guest

Jump to the latest result

Object lookup

Array lookup

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):