Benchmark: Javascript slice vs substring vs replace vs replaceall

Script Preparation code:

var text = '--bing';

Tests:

Substring
text = text.substring(2, text.length);
Slice
text = text.slice(2, text.length);
Substr
text = text.substr(2, text.length);
Replace
text = text.replace("--", "")
ReplaceAll
text = text.replaceAll("--", "")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Substring
Slice
Substr
Replace
ReplaceAll

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Substring	17266220.0 Ops/sec
Slice	17243420.0 Ops/sec
Substr	17341842.0 Ops/sec
Replace	16427916.0 Ops/sec
ReplaceAll	12698046.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the JavaScript microbenchmarking test on MeasureThat.net.

**Benchmark Definition**
The benchmark definition is a JSON object that represents the script and HTML preparation code for each test case. In this case, the script preparation code is the same for all test cases: `var text = '--bing';`. This means that the input string is initialized with the value `--bing`.

**Test Cases**
There are four test cases:

1. **Substring**: The benchmark definition is `text = text.substring(2, text.length);`, which attempts to extract a substring starting from index 2 up to the end of the string.
2. **Slice**: The benchmark definition is `text = text.slice(2, text.length);`, which is similar to Substring but uses the `slice()` method instead.
3. **Substr**: The benchmark definition is `text = text.substr(2, text.length);`, which uses the `substr()` method to extract a substring starting from index 2 up to the end of the string.
4. **Replace**: The benchmark definition is `text = text.replace("--", "");`, which attempts to replace all occurrences of `--` with an empty string using the `replace()` method.
5. **ReplaceAll**: The benchmark definition is `text = text.replaceAll("--", "");`, which is similar to Replace but uses the `replaceAll()` method instead.

**Options Compared**
The options compared in this benchmark are:

* Substring vs Slice: Both methods extract a substring from the input string, but Slice uses the `slice()` method, while Substring uses the `substring()` method.
* Substr vs Replace/ReplaceAll: The Substr method extracts a substring starting from index 2 up to the end of the string, while Replace and ReplaceAll replace all occurrences of `--` with an empty string.

**Pros and Cons**

* **Substring vs Slice**: Slice is generally faster because it's implemented in native code (C++), while Substring is implemented in JavaScript (interpreted). However, the difference is usually negligible unless you're working with very large strings.
* **Substr vs Replace/ReplaceAll**: The replace methods are likely to be slower than the substring/slice methods because they involve iterating over the entire string and making changes. Additionally, Substr extracts a fixed-length substring, while Replace/ReplaceAll can affect the performance of subsequent operations if not handled correctly.

**Library**
None of the test cases use any external libraries.

**Special JS Feature or Syntax**
There are no special JavaScript features or syntax used in these benchmark definitions.

**Other Considerations**

* The input string `--bing` is short and simple, which might affect the results. In a real-world scenario, you'd want to test with longer strings.
* The tests are run on Chrome 128, but it's possible that other browsers or versions of JavaScript would produce different results.

**Alternatives**
If you were to create similar benchmarks for other string manipulation methods in JavaScript, some alternatives could include:

* Using larger input strings to see the impact on performance
* Comparing the performance of different browsers or environments
* Adding additional operations after the main benchmarked operation (e.g., concatenation, splitting) to simulate real-world use cases
* Using a different set of string manipulation methods, such as regular expressions or internationalization functions.

Related benchmarks:

Javascript slice vs substring vs replace vs replaceall (version: 0)

Comparing performance of: Substring vs Slice vs Substr vs Replace vs ReplaceAll

Created: 3 years ago by: Guest

Jump to the latest result

Substring

Slice

Substr

Replace

ReplaceAll

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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