Benchmark: slice VS splice VS shif vs substr vs substring

Script Preparation code:

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

Tests:

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

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Measuring the performance of different string manipulation techniques in JavaScript can be helpful for web developers who need to optimize their code for better performance.

The benchmark tests four common string manipulation methods:

1. `slice()`: Returns a new string slice from the original array, excluding the first n characters.
2. `splice()`: Removes or replaces elements within an array and returns the removed elements.
3. `shift()`: Removes the first element from an array and returns it.
4. `substr()` (or `substring()`) : Returns a substring of the original string, starting at a specified position.

Here's a brief explanation of each approach:

**`slice()`**: This method is often faster than other methods because it doesn't modify the original array. It creates a new array with the desired characters, which can be more expensive in terms of memory usage.

Pros: Fast and efficient; doesn't modify the original array.
Cons: Creates a new array, which can consume more memory.

**`splice()`**: This method modifies the original array by removing or replacing elements at a specified position. It's not as efficient as `slice()` because it involves modifying the array.

Pros: Modifies the original array, so no extra memory is used.
Cons: Slower than `slice()` due to modification of the array.

**`shift()`**: This method removes the first element from an array and returns it. Like `splice()`, it modifies the original array.

Pros: Removes only one element from the array, which can be efficient for small arrays.
Cons: Modifies the original array; slower than `slice()` for large arrays.

**`substr()` (or `substring()`)`: These methods return a substring of the original string, starting at a specified position. They're often slower than `slice()` because they involve creating new strings or arrays.

Pros: Returns a subset of the original string, which can be useful in certain situations.
Cons: Slower and more memory-intensive than `slice()`

The benchmark results show that:

* `slice()` is the fastest method, followed closely by `substr()` (or `substring()`).
* `splice()` is slower due to its modification of the array.
* `shift()` is relatively slow due to its removal of the first element from the array.

Other alternatives to these methods include:

* Using regular expressions to extract substrings
* Utilizing libraries like Lodash or Ramda, which provide optimized string manipulation functions
* Converting strings to arrays using `split()` or `splitter()` and then applying array operations

It's worth noting that the performance differences between these methods can be negligible in many cases. However, for critical performance-critical code, choosing the right method can make a significant difference.

When to use each method:

* Use `slice()` when you need to extract a subset of an array without modifying it.
* Use `splice()` when you need to modify the original array or remove elements at a specific position.
* Use `shift()` when you need to remove only one element from an array and don't care about the removed value.
* Use `substr()` (or `substring()`) when you need to extract a subset of a string and can afford the extra memory usage.

In general, if you're working with arrays or strings in JavaScript, it's essential to understand the performance characteristics of different methods to optimize your code for better performance.

Related benchmarks:

slice VS splice VS shif vs substr vs substring (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):