Benchmark: regex vs filter - MeasureThat.net

Tests:

regex
function removeCharFrom(str, char) { const regex = new RegExp(`${char}`, "gi"); return str.replace(regex, ""); } console.log(removeCharFrom("ElddzeroD WebDD ddSchool", "d"));
filter
function removeCharFrom(str, char) { return str .split("") .filter((c) => c != char.toLowerCase() && c != char.toUpperCase()) .join(""); } console.log(removeCharFrom("ElddzeroD WebDD ddSchool", "d"));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
filter

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/136.0.0.0 Safari/537.36

Browser/OS: Chrome 136 on Windows

View result in a separate tab

Test name	Executions per second
regex	368205.0 Ops/sec
filter	248907.1 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 is being tested.

**Benchmark Definition**

The benchmark is defined by two test cases:

1. `regex`
2. `filter`

Both tests are designed to measure the performance of removing a specific character from a string.

**Script Preparation Code and Html Preparation Code**

Since there is no script preparation code or html preparation code provided in the benchmark definition, it's likely that these steps are handled automatically by MeasureThat.net or are not relevant to the comparison being made.

**Test Cases**

Let's analyze each test case:

### `regex`

This test case uses a regular expression (regex) to remove the specified character from the string. The regex pattern is created using a template literal, which allows for dynamic creation of the pattern.

```javascript
const regex = new RegExp(`${char}`, "gi");
```

The `"g"` flag at the end of the pattern makes it match all occurrences in the string, not just the first one.

The `replace()` method is then used to replace the matched characters with an empty string, effectively removing them from the original string.

### `filter`

This test case uses the `Array.prototype.filter()` method to remove the specified character from the string. The idea is to split the string into individual characters, filter out the unwanted characters, and then join the remaining characters back together.

```javascript
return str
  .split("")
  .filter((c) => c != char.toLowerCase() && c != char.toUpperCase())
  .join("");
```

**Options Compared**

The two test cases compare the performance of using a regular expression to remove a character from a string versus using the `Array.prototype.filter()` method.

**Pros and Cons**

Here's a brief summary:

* **Regex**:
	+ Pros:
		- Can be more efficient for certain use cases, such as when removing a specific set of characters.
		- Allows for more complex pattern matching and replacement.
	+ Cons:
		- Can be slower due to the overhead of creating and compiling the regex pattern.
		- May not be suitable for very large strings or performance-critical applications.
* **Filter**:
	+ Pros:
		- Often faster and more lightweight than using regex.
		- Can be more memory-efficient, as it only processes individual characters rather than entire patterns.
	+ Cons:
		- May not support all the features of regex, such as complex pattern matching or replacement.

**Other Considerations**

When choosing between these two approaches, consider the specific requirements of your use case. If you need to remove a small set of characters from a string and don't mind the overhead of creating and compiling a regex pattern, `regex` might be sufficient. However, if you're working with very large strings or performance is critical, using `filter` could provide better results.

**Alternative Approaches**

If none of these approaches suit your needs, other alternatives include:

* Using `String.prototype.replace()` with a callback function to filter out unwanted characters.
* Utilizing specialized libraries or frameworks that optimize string manipulation for performance.
* Exploring native WebAssembly (WASM) or other low-level optimizations for high-performance string processing.

Keep in mind that these alternatives might require additional setup, expertise, and resources.

Related benchmarks:

regex vs filter (version: 0)

Comparing performance of: regex vs filter

Created: 2 years ago by: Guest

Jump to the latest result

regex

filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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