Benchmark: js replace vs substr

Script Preparation code:

var strIn = '@mol-fe/mol-fe-webpush-server-worker';
var strOut = '';

Tests:

replace
strOut = strIn.replace('@mol-fe/mol-fe-', '');
substr
strOut = strIn.substr(15);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replace
substr

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:122.0) Gecko/20100101 Firefox/122.0

Browser/OS: Firefox 122 on Windows

View result in a separate tab

Test name	Executions per second
replace	27585752.0 Ops/sec
substr	600705472.0 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 benchmark test and explain what's being tested, compared, and other considerations.

**Benchmark Definition**

The benchmark is testing two different approaches to replace or remove a substring from a string in JavaScript:

1. `strOut = strIn.replace('@mol-fe/mol-fe-', '');`
2. `strOut = strIn.substr(15);`

**Options Compared**

Two options are being compared: `replace` and `substr`.

**Pros and Cons of Each Approach**

1. **Replace**
	* Pros:
		+ More concise and readable code.
		+ Can be more efficient if the replacement string is short.
	* Cons:
		+ May have a higher overhead due to the use of a regular expression engine.
2. **Substr**
	* Pros:
		+ Can be more efficient for large strings or when working with character indices.
	* Cons:
		+ More verbose and less readable code.

**Library Usage**

The benchmark uses the `replace` method, which is part of the JavaScript Standard Library (ECMAScript). The purpose of this library is to provide a set of standard functions for manipulating strings, arrays, and other data types.

**Special JS Feature or Syntax**

There's no special JavaScript feature or syntax being used in this benchmark. Both approaches are standard JavaScript methods.

**Other Considerations**

1. **Performance**: The benchmark measures the execution speed of each approach. Faster execution times indicate better performance.
2. **Code Readability and Maintainability**: While `substr` is more verbose, it's often preferred for its clarity and predictability when working with character indices.
3. **String Handling**: When dealing with large strings or complex replacements, using a library like RegEx can be beneficial. However, in this benchmark, the replacement string is relatively short.

**Alternatives**

Other alternatives to `replace` and `substr` include:

1. Using a custom implementation: If you have specific requirements or need more control over the substring removal process.
2. Using other JavaScript methods:
	* `indexOf()`, `slice()`, and `concat()` can be used in combination to achieve similar results as `replace`.
3. Utilizing third-party libraries: Depending on your use case, libraries like [Lodash](https://lodash.com/) or [Ramda](https://ramdajs.com/) might provide more efficient or convenient substring removal functions.

In summary, the benchmark is testing two common JavaScript methods for removing substrings from strings, evaluating their performance and code readability.

Related benchmarks:

js replace vs substr (version: 0)

Test of replace vs substr

Comparing performance of: replace vs substr

Created: 5 years ago by: Guest

Jump to the latest result

replace

substr

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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