Benchmark: Lodash DifferenceWith vs Native with Object

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.4/lodash.min.js"></script>

Script Preparation code:

const makeObject= (id) => {
  id
}
const fillArray = (nb)=> {
  let array = [];
  for(let i = nb; i>0; i--){
    array.push(makeObject(i));
  }
  return array;
}
var oldArr = fillArray(100)

var newArr = fillArray(200)

Tests:

Native
newArr.reduce((ids, obj) => { return ids.concat( !oldArr.some(oldItem => _.isEqual(oldItem,obj)) ? obj : [] ); }, [])
Lodash.js filter
_.differenceWith(newArr, oldArr, _.isEqual);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Native
Lodash.js 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.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark measures the performance difference between two approaches:

1. Native JavaScript implementation
2. Using the Lodash library's `differenceWith` function

**Native Implementation**

The native implementation uses the built-in JavaScript methods to achieve the same result as the Lodash `differenceWith` function. In this case, it uses the `reduce` method and the `some` method with a callback function.

Here's a simplified explanation of the code:

```javascript
newArr.reduce((ids, obj) => {
  return ids.concat(
    !oldArr.some(oldItem => _.isEqual(oldItem, obj)) ? obj : []
  );
}, [])
```

The native implementation works by iterating over the `newArr` array and for each element, it checks if there's an existing element in `oldArr` that is equal to the current element using the `_` (lodash) function. If no such element exists, it concatenates the current object with the accumulator (`ids`). This way, the native implementation achieves a similar result as the Lodash `differenceWith` function without relying on a library.

**Lodash Library**

The Lodash library is a popular JavaScript utility library that provides a wide range of functions for various tasks, including array manipulation, string manipulation, and more. The `differenceWith` function is specifically designed to find the difference between two arrays using a custom comparison function.

In this benchmark, the Lodash `differenceWith` function takes three arguments:

* `newArr`: the first array
* `oldArr`: the second array
* `isEqual`: the comparison function

The `_` (lodash) library is used in the native implementation to access its functions. This suggests that the test environment uses a bundled version of Lodash, which includes all its functions.

**Pros and Cons**

Here are some pros and cons of each approach:

Native Implementation:

Pros:

* No external dependency on the Lodash library
* May be faster due to fewer function calls

Cons:

* More complex code
* Requires careful implementation to achieve the same result as `differenceWith`

Lodash Library (specifically, `differenceWith`):

Pros:

* Easier to implement and maintain
* Well-tested and widely used

Cons:

* External dependency on the Lodash library
* May be slower due to function call overhead

**Other Considerations**

When writing a benchmark like this, it's essential to consider other factors that might impact performance, such as:

* Cache locality: How well do the arrays align in memory? This can affect cache performance.
* Branch prediction: How often does the `some` method branch predict correctly?
* Loop unrolling: Can the native implementation be optimized using loop unrolling techniques?

**Alternatives**

If you're looking for alternative libraries or implementations, consider:

* `Array.prototype.filter()`: A more straightforward approach that doesn't rely on a custom comparison function.
* `lodash-unique`: Another Lodash library that provides an `unaryWith` function similar to `differenceWith`.
* Custom implementation using bitwise operations: This can be a highly optimized solution but requires careful implementation and testing.

Keep in mind that the best approach will depend on your specific use case, performance requirements, and personal preferences.

Related benchmarks:

Lodash DifferenceWith vs Native with Object (version: 0)

Comparing performance of: Native vs Lodash.js filter

Created: 3 years ago by: Guest

Jump to the latest result

Native

Lodash.js 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):