Benchmark: slice vs substr vs substring with end

Script Preparation code:

var example = 'there is no spoon'

Tests:

slice
var result = example.slice(0,-1)
substr
var result = example.substr(10)
substring
var result = example.substring(0,example.length - 1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
substr
substring

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36

Browser/OS: Chrome 139 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	260353952.0 Ops/sec
substr	245863424.0 Ops/sec
substring	292488192.0 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the benchmark test case.

**What is being tested?**

The benchmark is comparing three different ways to extract a substring from a string in JavaScript: `slice`, `substr`, and `substring`.

**Description of options**

1. **`slice`**: The `slice` method is used to extract a section of an array or a subset of characters from a string. In this test case, it's being used to extract the last character from the string `'there is no spoon'`. The syntax is `string.slice(startIndex)`, where `startIndex` is the position where you want to start extracting characters.
2. **`substr`**: The `substr` method (which is deprecated in modern JavaScript) is used to extract a subset of characters from a string, starting at a specified index and optionally ending at another index. In this test case, it's being used to extract the substring starting from index 10 (i.e., `'o no spoon'`) without specifying an end index.
3. **`substring`**: The `substring` method is similar to `substr`, but it requires two indices: one for the start position and another for the end position. In this test case, it's being used to extract the substring from index 0 (i.e., the beginning of the string) to index `example.length - 1`, effectively excluding the last character.

**Pros and cons**

Here are some pros and cons of each method:

* **`slice`**: Pros: more modern and efficient; Cons: may be slower for large strings or edge cases.
* **`substr` (deprecated)**: Pros: None; Cons: slower, less efficient, and should not be used in new code.
* **`substring`**: Pros: simple to use and understand; Cons: may be slower for large strings or edge cases.

**Other considerations**

* The test case uses a string `'there is no spoon'`, which has a length of 16 characters. This might affect the performance comparison between the methods, as `slice` and `substring` need to calculate the end index.
* The test case is running on Firefox 74, so the results may vary on other browsers or JavaScript engines.

**Library**

No external library is used in this benchmark.

**Special JS feature or syntax**

None are mentioned in this specific test case. However, note that `slice` and `substring` methods use a different indexing approach than `substr`, where indices start from 0 instead of the position immediately after the string's first character.

Related benchmarks:

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

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

Comparing performance of: slice vs substr vs substring

Created: 6 years ago by: Guest

Jump to the latest result

slice

substr

substring

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):