Benchmark: slice vs substring (with end index)

Script Preparation code:

var example = 'there is no spoon'

Tests:

slice
var result = example.slice(10, -1)
substring
var result = example.substring(10, example.length-1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substring

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
slice	67914480.0 Ops/sec
substring	59259968.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is comparing three string manipulation methods in JavaScript: `slice()`, `substring()`, and `substr()` (note that `substr()` is not explicitly mentioned in the benchmark definition, but it will be discussed later). The benchmark tests how fast each method performs when given a specific input string (`"there is no spoon"`).

**Options Compared**

The two main options being compared are:

1. `slice()`: This method returns a new string containing the characters from the specified start index (10) to the end of the string.
2. `substring()`: This method returns a new string containing the characters from the specified start index (10) to the specified end index (exclusive, i.e., -1).

**Pros and Cons**

* **slice()**: Pros: generally faster than `substring()` since it doesn't need to check if the start or end indices are within the bounds of the string. Cons: returns a new string, which can be inefficient in memory.
* **substring()**: Pros: does not return a new string (returns an index into the original string), which can be more efficient in terms of memory allocation. Cons: slower than `slice()` due to the additional check.

**substr()**

Although not explicitly mentioned in the benchmark definition, `substr()` is worth mentioning as it's a similar method to `substring()`. The main difference is that `substr()` does not require an explicit end index and will continue until the specified start index. However, this can lead to unexpected behavior if the input string is shorter than the start index. In general, `substr()` is considered less efficient than `slice()` due to its flexibility.

**Library and Special JS Features**

None of the methods being compared require any external libraries or special JavaScript features beyond basic understanding of strings and array methods. The benchmark only requires standard JavaScript functionality.

**Other Considerations**

When choosing between these methods, consider the following:

* If you need to frequently manipulate strings in a specific range, `slice()` might be a better choice due to its efficiency.
* If you're working with large strings or need to minimize memory allocation, `substring()` could be a better option.

**Alternatives**

Other alternatives for string manipulation methods include:

* Using regular expressions (`RegExp`) for pattern matching and replacement.
* Employing string interpolation using template literals (`template literals`).
* Utilizing the `String.prototype.replace()` method for character-by-character replacements.

In summary, this benchmark provides valuable insights into the performance differences between various JavaScript string manipulation methods. By understanding these trade-offs, developers can make informed decisions about which methods to use depending on their specific use case and requirements.

Related benchmarks:

slice vs substring (with end index) (version: 0)

Compares slice, substr and substring to each other when there is only a start index

Comparing performance of: slice vs substring

Created: 3 years ago by: Guest

Jump to the latest result

slice

substring

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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