Benchmark: String.Replace(2x) vs String.substring

Script Preparation code:

str = '{teststring}'

Tests:

String.Replace
str.replace('{', '').replace('}', '');
String.substring
str.substring(1,str.length-1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.Replace
String.substring

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into explaining what is tested in the provided JSON benchmark for MeasureThat.net.

**Benchmark Definition**

The benchmark measures the performance difference between two string manipulation methods: `String.replace()` and `String.substring()`. The test case consists of two individual tests, each with a different approach to replace a substring within a test string.

**Options Compared**

In this benchmark, the following options are compared:

1. **`String.replace()`**: This method replaces all occurrences of a specified pattern (in this case, `'{', '}'`) in a given string.
2. **`String.substring()`**: This method extracts a portion of a string, starting from a specified index and ending at another specified index.

**Pros and Cons**

Here are some pros and cons for each approach:

*   **`String.replace()`**:
    *   Pros: Generally more efficient than `String.substring()`, as it eliminates the need to create intermediate substrings.
    *   Cons: May be slower when dealing with large replacements, due to the overhead of creating multiple replacement strings. Additionally, this method does not support regular expressions by default, which may limit its applicability in certain scenarios.

*   **`String.substring()`**:
    *   Pros: Can handle complex substring extraction using the `match()` and `slice()` methods.
    *   Cons: Creates intermediate substrings, which can be slower than using `String.replace()`. Additionally, this method requires explicit index calculations or uses, making it less convenient for simple string manipulation tasks.

**Library and Special JS Features**

There is no specific JavaScript library being used in this benchmark. However, the use of template literals (`{teststring}`) and string interpolation (e.g., `{}`) might be considered ES6+ syntax features. These features allow for more readable and concise code, but may not be supported by older browsers or versions of JavaScript.

**Alternatives**

Some alternatives to `String.replace()` and `String.substring()` include:

*   **`String.prototype.split()`**: This method splits a string into an array of substrings based on a specified separator.
*   **`Array.prototype.map()`**: This method applies a transformation function to each element in an array, which can be useful for iterating over characters or substrings in a string.

**Other Considerations**

When choosing between `String.replace()` and `String.substring()`, consider the following factors:

*   **Performance**: If you need to replace multiple occurrences of a substring, `String.replace()` might be faster.
*   **Complexity**: If you're dealing with complex substring extraction or manipulation tasks, `String.substring()` with its use of regular expressions or `match()` and `slice()` methods might be more suitable.
*   **Convenience**: If you need to perform simple string manipulation tasks, `String.replace()` might be a more convenient choice due to its simplicity and readability.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36

Browser/OS: Chrome 88 on Windows

View result in a separate tab

Test name	Executions per second
String.Replace	1922215.5 Ops/sec
String.substring	2404058.0 Ops/sec

Related benchmarks:

String.Replace(2x) vs String.substring (version: 0)

Comparing performance of: String.Replace vs String.substring

Created: 3 years ago by: Guest

Jump to the latest result

String.Replace

String.substring

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):