Benchmark: Remove items from array vs from objects

Tests:

Splice (first item)
const a = [{id: "a"}, {id: "b"}, {id: "c"}, {id: "d"}, {id: "e"}, {id: "f"},{id: "g"},{id: "h"},{id: "i"},{id: "j"},{id: "k"},{id: "l"}]; const indexToRemove = a.findIndex(i => i === "a"); const b = a.splice(indexToRemove, 1);
Splice (last item)
const a = [{id: "a"}, {id: "b"}, {id: "c"}, {id: "d"}, {id: "e"}, {id: "f"},{id: "g"},{id: "h"},{id: "i"},{id: "j"},{id: "k"},{id: "l"}]; const indexToRemove = a.findIndex(i => i === "l"); const b = a.splice(indexToRemove, 1);
Filter (first item)
const a = [{id: "a"}, {id: "b"}, {id: "c"}, {id: "d"}, {id: "e"}, {id: "f"},{id: "g"},{id: "h"},{id: "i"},{id: "j"},{id: "k"},{id: "l"}]; const b = a.filter(item => item.id !== "a")
Filter (last item)
const a = [{id: "a"}, {id: "b"}, {id: "c"}, {id: "d"}, {id: "e"}, {id: "f"},{id: "g"},{id: "h"},{id: "i"},{id: "j"},{id: "k"},{id: "l"}]; const b = a.filter(item => item.id !== "l")
Remove object key (first)
const a = { a: {key: true}, b: {key: true}, c: {key: true}, d: {key: true}, e: {key: true}, f: {key: true}, g: {key: true}, h: {key: true}, i: {key: true}, j: {key: true}, k: {key: true}, l: {key: true} } a.a = undefined
Remove object key (last)
const a = { a: {key: true}, b: {key: true}, c: {key: true}, d: {key: true}, e: {key: true}, f: {key: true}, g: {key: true}, h: {key: true}, i: {key: true}, j: {key: true}, k: {key: true}, l: {key: true} } a.l = undefined

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Splice (first item)
Splice (last item)
Filter (first item)
Filter (last item)
Remove object key (first)
Remove object key (last)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:134.0) Gecko/20100101 Firefox/134.0

Browser/OS: Firefox 134 on Windows

View result in a separate tab

Test name	Executions per second
Splice (first item)	7137730.5 Ops/sec
Splice (last item)	5756173.5 Ops/sec
Filter (first item)	6755804.0 Ops/sec
Filter (last item)	5773236.5 Ops/sec
Remove object key (first)	21080100.0 Ops/sec
Remove object key (last)	20245240.0 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided JSON represents a benchmark test for measuring the performance of different JavaScript methods for removing items from arrays and objects.

**What is being tested:**

1. Removing items from an array using `splice()` (specifically, finding the index of the item to be removed and then splicing it out).
2. Removing items from an object by modifying its key-value pairs.
3. Filtering out specific items from an array or object using `filter()`.

**Options being compared:**

1. Finding the index of the item to be removed (`findIndex()`) followed by `splice()`.
2. Removing the first and last item from an array/object.
3. Removing a specific key-value pair from an object (`a.key = undefined`).

**Pros and cons of each approach:**

1. **Finding the index and then using `splice()`**: This method is straightforward but may incur additional overhead due to the extra step of finding the index. It's often faster, but its performance can be variable depending on the array length and distribution.
2. **Removing the first item from an array/object**: This method is simple and has a small constant factor, making it a good choice for short arrays or objects. However, it may not be suitable for larger datasets where the overhead of iterating over the entire array/object outweighs any potential benefits.
3. **Removing the last item from an array/object**: Similar to removing the first item, this method is simple and has a small constant factor. It's also often faster than finding the index and then using `splice()`.
4. **Removing a specific key-value pair from an object**: This method can be slower than others since it involves iterating over the entire object to find the matching key.

**Browser-specific observations:**

The provided raw UA strings indicate that all tests were run on Chrome 88, with various device platforms and operating systems (Windows). The performance results suggest that:

* Removing items from an array using `splice()` is relatively fast.
* Filtering out specific items from an array using `filter()` is faster than removing the first or last item.
* Removing a specific key-value pair from an object can be slower than other methods.

**Device platform and operating system considerations:**

The performance results may vary depending on the device platform and operating system. For example:

* Desktop browsers like Chrome 88 tend to perform better than mobile browsers or Edge.
* Windows operating systems may have different performance characteristics compared to macOS or Linux.

It's essential to note that these findings are based on a specific benchmark test and may not generalize to all JavaScript scenarios or use cases.

Related benchmarks:

Remove items from array vs from objects (version: 0)

Comparing performance of: Splice (first item) vs Splice (last item) vs Filter (first item) vs Filter (last item) vs Remove object key (first) vs Remove object key (last)

Created: 5 years ago by: Guest

Jump to the latest result

Splice (first item)

Splice (last item)

Filter (first item)

Filter (last item)

Remove object key (first)

Remove object key (last)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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