Benchmark: indexOf + toSpliced vs. filter

Script Preparation code:

var arr = new Array(15000);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var idToFilter = Math.floor(Math.random() * 15000);

Tests:

indexOf + splice
var index = arr.indexOf(idToFilter); var newArray = arr.toSpliced(index, 1);
filter
var newArray = arr.filter(e => e.id !== idToFilter);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf + splice
filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 18 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Windows

View result in a separate tab

Test name	Executions per second
indexOf + splice	28558.8 Ops/sec
filter	10130.2 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 18 days ago):

LLMs can make mistakes. Check important info.

This benchmark evaluates two different approaches to remove an object from an array based on an identified index in JavaScript: using `indexOf` combined with `toSpliced`, versus using `filter`. Below is a detailed explanation of each approach, its pros and cons, and other considerations.

### Test Approaches

1. **`indexOf + toSpliced` Approach**
   - **Benchmark Definition**: `var index = arr.indexOf(idToFilter);\r\nvar newArray = arr.toSpliced(index, 1);`
   - **Test Name**: "indexOf + splice"

**Explanation**:
   - **`indexOf`**: This method returns the index of the first occurrence of a specified value in the array. In this case, it is used to find the index of the element that matches `idToFilter`.
   - **`toSpliced`**: This recent addition to JavaScript allows for the creation of a new array by removing elements from an existing one, identified by their index. It creates a new array without modifying the original.

**Pros**:
   - More efficient when needing to remove a single element and when the index of the element to remove is already known.
   - Creating a new array without affecting the original is beneficial for maintaining immutability, which can help avoid side effects in applications.

**Cons**:
   - The use of `indexOf` requires a linear search to find the index, making it less efficient if the element's position is not known or if the array is very large.
   - The complexity can compound if multiple elements need to be removed or if the search operation is repeated frequently.

2. **`filter` Approach**
   - **Benchmark Definition**: `var newArray = arr.filter(e => e.id !== idToFilter);`
   - **Test Name**: "filter"

**Explanation**:
   - **`filter`**: This method creates a new array with all elements that pass the test implemented by the provided function. In this scenario, it retains all elements whose `id` does not match `idToFilter`.

**Pros**:
   - More straightforward and intuitive when needing to filter multiple elements based on specific criteria.
   - It abstracts the logic of index searching and replacement, making it easy to read and maintain code.

**Cons**:
   - Performance might degrade for larger data sets as every entry is checked against the filter condition regardless of whether they need to be removed or not.
   - This approach leads to the creation of a new array with potentially more elements copied than necessary, depending on how many elements match the condition.

### Comparison of Performance

- **Executions Per Second**:
  - For the `indexOf + toSpliced` approach, the benchmark recorded approximately **28,558** executions per second.
  - For the `filter` approach, the recorded performance was significantly lower, at about **10,130** executions per second.

### Other Considerations

- **Immutability**: Both approaches are non-mutating, which is favorable in environments where state management is important, such as in functional programming paradigms or when using frameworks that rely on state changes.
  
- **Library and Language Features**: The benchmark does not utilize any external libraries, focusing solely on the capabilities provided by modern JavaScript. Hence, the benchmark comparisons directly reflect the performance of standard native array methods.

### Alternatives

1. **`splice` Method**: Instead of using `toSpliced`, one could use the `splice` method, which modifies the array in place. However, this would not adhere to immutability principles.

2. **Using a Set or Map**: For large datasets or frequent lookups, considering data structures like `Set` or `Map`, which offer O(1) complexity for checks, might yield performance benefits.

3. **Typed Arrays**: If performance is critical and data types can be assumed, Typed Arrays can be used for numeric calculations, offering a more efficient memory usage.

By understanding the differences between these approaches, software engineers can choose the best method based on the context of their application, prioritizing performance, code readability, and maintainability.

Related benchmarks:

indexOf + toSpliced vs. filter (version: 1)

Comparing performance of: indexOf + splice vs filter

Created: 18 days ago by: Guest

Jump to the latest result

indexOf + splice

filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 18 days ago):