Benchmark: Double for vs Object.values.flat

Script Preparation code:

var combined = {
    'parent_1': [
        'child_1',
        'child_2',
        'child_3'
    ],
    'parent_2': [
        'child_4',
        'child_5',
        'child_6'
    ],
    'parent_4': [
        'child_7',
        'child_8',
        'child_9'
    ]
};

var maybeDup = [
    'child_1',
    'child_5',
    'child_9',
    'child_10'
];

Tests:

Double for and filter
for (let i = 0; i < 10000; i++) { let dup = [...maybeDup]; for (let key in combined) { for (let val of combined[key]) { dup = dup.filter(x => x !== val); } } }
Object values, flat and filter
for (let i = 0; i < 10000; i++) { let dup = [...maybeDup]; for (let val of Object.values(combined).flat()) { dup = dup.filter(x => x !== val); } }
Set and filter
for (let i = 0; i < 10000; i++) { let dup = new Set(...maybeDup); for (let val of Object.values(combined)) { if (dup.has(val)) { dup.delete(val); } } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Double for and filter
Object values, flat and filter
Set and filter

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 the performance of JavaScript code is crucial for developers to optimize their applications. Let's break down what's being tested in this benchmark.

**Benchmark Goal**

The goal of this benchmark is to compare three different approaches for removing duplicates from an array:

1. **Double `for` loop**: This approach uses two nested loops to iterate over the array and remove duplicates.
2. **`Object.values().flat()` + `filter()`**: This approach uses the `Object.values()` method to get an array of values, then flattens it using `flat()`, and finally filters out duplicates using `filter()`.
3. **Set + `filter()`**: This approach creates a Set from the array and then iterates over the object's values to filter out duplicates.

**Approach Comparison**

Here's a brief summary of each approach:

* **Double `for` loop**: This approach is straightforward but may be slow due to the overhead of two loops.
* **`Object.values().flat()` + `filter()`**: This approach uses the modern JavaScript API and can be faster since it avoids explicit looping. However, it requires more memory allocation and copying of elements.
* **Set + `filter()`**: This approach is likely the fastest since it uses a data structure optimized for fast lookups (Sets) and has minimal overhead.

**Pros and Cons**

Here's a summary of each approach:

* **Double `for` loop**:
	+ Pros: Easy to understand, no additional library dependencies.
	+ Cons: May be slow due to two loops.
* **`Object.values().flat()` + `filter()`**:
	+ Pros: Modern JavaScript API, potentially faster.
	+ Cons: Requires more memory allocation and copying of elements.
* **Set + `filter()`**:
	+ Pros: Fastest approach, optimized for fast lookups.
	+ Cons: May require additional library dependencies (not shown in the benchmark), less intuitive.

**Library Usage**

In this benchmark, no libraries are explicitly mentioned. However, `Object.values()` is a modern JavaScript API that requires no additional libraries to use.

**Special JS Features/Syntax**

None of the approaches rely on special JavaScript features or syntax beyond what's commonly used in modern browsers.

**Alternatives**

Other approaches for removing duplicates from an array could include:

* Using `Array.prototype.reduce()` with a callback function.
* Utilizing a library like Lodash (which provides a `uniq` function).
* Implementing a custom solution using bit manipulation (e.g., XORing elements).

Keep in mind that the performance of these alternatives may vary depending on the specific use case and implementation.

Related benchmarks:

Double for vs Object.values.flat (version: 0)

Comparing performance of: Double for and filter vs Object values, flat and filter vs Set and filter

Created: 4 years ago by: Guest

Jump to the latest result

Double for and filter

Object values, flat and filter

Set and filter

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):