Benchmark: splice vs delete on different types

HTML Preparation code:

<script>
  const numArr = new Array(1e5).fill(1);
  const stringArr = new Array(1e5).fill('m1c6kzws0iubt8g0zlsug14i');
  const arrArr = new Array(1e5).fill([1,2,3]);
  const objArr = new Array(1e5).fill({a: 1});
  var array = [].concat(numArr, stringArr, objArr, arrArr);
  
</script>

Script Preparation code:

function deleteBySplice (array, index) {
  
  if (index !== -1) {
  	array.splice( index, 1 );
  }
}

function deleteByDelete (array, index) {
  
  if (index !== -1) {
  	delete array[index];
  }
}

Tests:

deleteBySplice
deleteBySplice( array, 1000002 ); deleteBySplice( array, 1 ); deleteBySplice( array, 2 );
deleteByDelete
deleteByDelete( array, 1000002 ); deleteByDelete( array, 1 ); deleteByDelete( array, 2 );

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
deleteBySplice
deleteByDelete

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark definition json contains two functions: `deleteBySplice` and `deleteByDelete`. Both functions are designed to delete an element at a specific index in an array. The main difference between them is how they achieve this deletion:

1. `deleteBySplice`: Uses the `splice` method, which modifies the original array by removing the specified element.
2. `deleteByDelete`: Uses the `delete` operator, which does not modify the original array but instead returns a boolean value indicating whether the operation was successful.

**Test Cases**

There are two test cases:

1. `deleteBySplice`
2. `deleteByDelete`

Both test cases create an array of different types (numbers, strings, and objects) and then perform the deletion operations on it. The test case for `deleteBySplice` calls the function with three indices: 1000002, 1, and 2.

**Options Compared**

The two options being compared are:

1. Using `splice` to delete an element from an array.
2. Using the `delete` operator to delete an element from an array.

**Pros and Cons of Each Approach**

**Splice:**

Pros:

* Modifies the original array, so no need to reassign the result.
* Can be more efficient for large arrays since it doesn't require creating a new array.

Cons:

* Can be slow for small arrays since it involves shifting elements after removal.
* Returns an array of the remaining elements after deletion.

**Delete Operator:**

Pros:

* Does not modify the original array, so no need to reassign the result.
* Can be faster for large arrays since it doesn't require creating a new array.
* Returns a boolean value indicating success or failure.

Cons:

* Requires reassigning the result (or assigning it to `undefined`).
* May have performance issues if not implemented correctly.

**Library and Special JS Feature**

The test case uses the JavaScript `Array.prototype.splice()` method, which is a built-in method for modifying arrays. There are no special JS features or syntax used in this benchmark.

**Other Alternatives**

If you were to rewrite these benchmarks using different approaches, here are some alternatives:

1. Using `filter` instead of `splice` or the delete operator.
2. Using a custom implementation that modifies the array's internal structure (e.g., by swapping elements).
3. Using a library like Lodash's `removeAt` function.

Keep in mind that each alternative would require different testing and analysis to determine performance differences.

**Benchmarking Considerations**

When benchmarking JavaScript functions, consider the following:

1. Use large arrays to test performance for large datasets.
2. Test with different array types (e.g., numbers, strings, objects).
3. Use repeatable seed values to ensure consistent results across multiple runs.
4. Avoid using optimized libraries or features that may skew results.

By understanding the pros and cons of each approach and considering these benchmarking considerations, you can make informed decisions when optimizing JavaScript code for performance.

Related benchmarks:

splice vs delete on different types (version: 0)

Comparing performance of: deleteBySplice vs deleteByDelete

Created: 6 years ago by: Guest

Jump to the latest result

deleteBySplice

deleteByDelete

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):