Benchmark: Slice vs Map (2222211111)

Tests:

slice
var item = 10; var index = 50; var array = Array.from({length: 100}); var array2 = [...array.slice(0, index), item, ...array.slice(index + 1)];
map
var item = 10; var index = 50; var array = Array.from({length: 100}).map((val, i) => i === index ? item : val);

Historical Performance Data aggregated from 29 community runs

Desktop Results:

Chrome 22 runs

map

240K/s

slice

234K/s

View exact numbers

✓ map: 239,732 ops/sec
• slice: 233,692 ops/sec

Firefox 7 runs

map

1.0M/s

slice

844K/s

Fastest: map (1.2x faster)

View exact numbers

✓ map: 1,019,192 ops/sec
• slice: 843,655 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36 Edg/147.0.0.0

Browser/OS: Chrome 147 on Windows

View result in a separate tab

slice

134K/s

map

131K/s

View exact numbers

Test name	Executions per second
✓ slice	134,015 Ops/sec
map	131,317 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided benchmark.

**Overview**

The benchmark is comparing two approaches to create an array by concatenating and slicing another array:

1. Using `Array.prototype.slice()` method with `array.slice(0, index), item, ...array.slice(index + 1)`
2. Using `Array.prototype.map()` function with a callback function that returns either the original value or a custom value (`item`) at the specified index.

**Options compared**

The benchmark is comparing two options:

1. **Slice method**: This approach uses the `slice()` method to create new arrays, which can be slower than other methods because it creates new objects.
2. **Map function**: This approach uses the `map()` function with a callback function that returns either the original value or a custom value (`item`) at the specified index.

**Pros and Cons**

* **Slice method**:
	+ Pros: Simple and easy to read, can be efficient if used correctly (avoiding unnecessary object creation).
	+ Cons: Can be slower than other methods due to object creation.
* **Map function**:
	+ Pros: Can be more concise and expressive, can avoid unnecessary object creation.
	+ Cons: May require additional library dependencies (e.g., for browser compatibility) or can be slower due to function call overhead.

**Library usage**

There is no explicit library mentioned in the benchmark definition. However, it's worth noting that `Array.prototype.slice()` and `Array.prototype.map()` are built-in methods on arrays in JavaScript.

**Special JS feature/syntax**

There are no special JavaScript features or syntax used in this benchmark. It only uses standard ECMAScript syntax for array manipulation.

**Other alternatives**

If you're looking for alternative approaches, consider the following:

1. **Using `Array.prototype.forEach()`**: This method can be more concise and expressive than `map()`, but it doesn't return an array.
2. **Using `Array.prototype.reduce()`**: This method can be used to create a new array by accumulating elements from an existing array, but it's not directly applicable here.
3. **Using a custom loop**: You could write a simple loop to concatenate and slice the arrays, but this approach would likely be slower than the built-in methods.

In general, when working with arrays in JavaScript, `map()` is often a good choice for transformations, while `slice()` can be used for more complex array manipulations.

Slice vs Map (2222211111) (version: 0) Benchmark.js

Comparing performance of: `slice vs map`

Created: 5 years ago by: Registered User

Go to the latest result

slice

map

Historical Performance Data aggregated from 29 community runs

Desktop Results:

Chrome 22 runs

Firefox 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Slice vs Map (2222211111) (version: 0) Benchmark.js

Comparing performance of: slice vs map

Created: 5 years ago by: Registered User

Go to the latest result

slice

map

Historical Performance Data aggregated from 29 community runs

Desktop Results:

Chrome 22 runs

Firefox 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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Comparing performance of: `slice vs map`