Benchmark: slice VS splice VS shif vs substr vs substring short

Script Preparation code:

var list = [];
for (var i = 0; i < 1000; i++) {
  list.push("IDqualcosaltro"+i);
}

Tests:

slice
for (var i = 0; i < 1000; i++) { list.push("IDqualcosaltro"+i); [...list[i]].slice(2); }
splice
for (var i = 0; i < 1000; i++) { list.push("IDqualcosaltro"+i); [...list[i]].splice(2); }
shift
for (var i = 0; i < 1000; i++) { list.push("IDqualcosaltro"+i); let tmp =[...list[i]] tmp.shift(); tmp.shift(); tmp.toString().replaceAll(',','') }
substr
for (var i = 0; i < 1000; i++) { list.push("IDqualcosaltro"+i); list[i].substr(2); }
substring
for (var i = 0; i < 1000; i++) { list.push("IDqualcosaltro"+i); list[i].substring(2); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
splice
shift
substr
substring

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 the pros/cons of each approach.

**Benchmark Overview**

The benchmark is designed to compare the performance of different methods for extracting a subset of characters from an array or string in JavaScript. The tests are:

1. `slice`: Extracts 2 characters from the end of an array using `array.slice(start)`.
2. `splice`: Removes 2 elements from the end of an array using `array.splice(start, length)`.
3. `shift`: Shifts the first two elements of an array and converts it to a string.
4. `substr` (not `substring`, as in some other languages): Extracts 2 characters from the end of a string using `string.substr(start)`.
5. `substring`: Extracts 2 characters from the end of a string using `string.substring(start)`.

**Library and Special JS Features**

None of these tests explicitly use any libraries, but they do utilize JavaScript's built-in features:

* Arrays: `array.slice()`, `array.splice()`
* Strings: `string.substr()`, `string.substring()`

**Comparison**

Each test case extracts 2 characters from the end of an array or string and measures the performance. The goal is to determine which method is the fastest.

**Pros and Cons of Each Approach**

1. **`slice()`**: Pros:
	* Efficient, as it only creates a new array slice.
	* Simple and easy to implement.
Cons:
	* Can be slower than `splice()` or `shift()` if the array is very large, as it requires creating a new array.
2. **`splice()`**: Pros:
	* Can be faster for large arrays, as it modifies the original array.
Cons:
	* More complex and harder to implement correctly.
	* May be slower than `slice()` for small arrays due to the overhead of modifying the array.
3. **`shift()`**: Pros:
	+ Fastest approach, as it only requires two operations: shifting elements and converting to a string.
Cons:
	+ Less flexible, as it shifts all elements before the specified index.
4. **`substr()`** (not `substring()`): Pros:
	+ Similar to `slice()`, but uses string methods instead of array methods.
Cons:
	+ Inefficient for large arrays or strings, as it requires creating a new string.
5. **`substring()`**: Pros:
	+ Similar to `slice()`, but uses string methods instead of array methods.
Cons:
	+ Inefficient for large arrays or strings, as it requires creating a new string.

**Other Alternatives**

There are other ways to achieve the same result without using these approaches:

* Using regular expressions: `new RegExp('\\d{2}$').exec('IDqualcosaltro' + i)[0]`
* Using `indexOf()` and slicing: `list[i].slice(list[i].indexOf('IDqualcosaltro' + i) + 5)` (note that this assumes the index is known in advance)
* Using a library like Lodash's `chunkAt()`: `_list.chunkAt(2)`
* Using a custom solution with a loop and conditional statements

Keep in mind that these alternatives may not be as efficient or simple to implement as the original methods.

Related benchmarks:

slice VS splice VS shif vs substr vs substring short (version: 0)

Comparing performance of: slice vs splice vs shift vs substr vs substring

Created: 4 years ago by: Guest

Jump to the latest result

slice

splice

shift

substr

substring

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):