Benchmark: regex vs indexOf

Tests:

regex
var result = 0; FILTERS = /\s*\|\s*([^\|\s:}]*)(?::((?:(?:[^\|\s,}]*),?)+))?\s*/g; var str = "{{value|filter:arg1,arg2|otherFilter}}"; for (var i=0; i < 1000; i++) { typeof str.match(FILTERS) !== null ? result += 1 : result += 0; }
indexOf
var result = 0; FILTERS = /\s*\|\s*([^\|\s:}]*)(?::((?:(?:[^\|\s,}]*),?)+))?\s*/g; var str = "{{value|filter:arg1,arg2|otherFilter}}"; for (var i=0; i < 1000; i++) { typeof str.indexOf('|') >= 0 ? result += 1 : result += 0; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex
indexOf

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided benchmark and explain what is being tested.

The benchmark compares two approaches to find a specific pattern in a string: regular expression (regex) and the `indexOf` method.

**Test Case 1: Regex**

In this test case, a regex filter `FILTERS` is defined using the `/.../g` syntax. The filter matches any character that is not a pipe (`|`) or a colon (`:`), as long as it's followed by an optional comma-separated list of values, and then optionally followed by a semicolon (`;`). The test case creates a string `str` with a template syntax `${value|filter:arg1,arg2|otherFilter}`, where the filter is applied to the first argument `arg1` and `arg2`. The test iterates 1000 times and increments a counter for each match found using `str.match(FILTERS)`, or increments it by zero if no match is found.

**Test Case 2: indexOf**

In this test case, the same filter `FILTERS` is used as in Test Case 1. However, instead of using regex, it uses the `indexOf` method to find the index of the first occurrence of the pipe (`|`) character in the string `str`. The test iterates 1000 times and increments a counter for each match found, or increments it by zero if no match is found.

**Comparison**

The benchmark compares the execution time of these two approaches on the same input data.

**Pros and Cons:**

* **Regex**:
	+ Pros:
		- More flexible and powerful for complex pattern matching.
		- Can be more efficient than `indexOf` in some cases, especially with large inputs.
	+ Cons:
		- Generally slower than `indexOf` due to the overhead of parsing and compiling regex patterns.
		- Can be less readable and maintainable, especially for simple patterns.
* **indexOf**:
	+ Pros:
		- Faster execution time compared to regex for simple pattern matching.
		- More concise and readable code.
	+ Cons:
		- Less flexible and powerful than regex for complex pattern matching.

**Library/Functionality:**

* `String.prototype.match()`: This method returns an array containing the matched strings if a match is found, or `null` otherwise. It's used to implement the regex filter in Test Case 1.
* `String.prototype.indexOf()`: This method returns the index of the first occurrence of the specified value in the string. If no match is found, it returns `-1`.

**Special JS Feature/Syntax:**

The template syntax `${value|filter:arg1,arg2|otherFilter}` is used in both test cases. This syntax is a feature of the Mustache templating engine, but it's also commonly used in other JavaScript libraries and frameworks for string interpolation.

**Alternatives:**

* For simple pattern matching, you can use regular expressions with the `/.../` syntax.
* For faster execution time, you can use the `indexOf` method or a library like Lodash's `findIndex()` function.
* For more flexibility and power in regex pattern matching, you can use a dedicated regex engine like RegEx.js.

I hope this explanation helps software engineers understand the benchmark and its implications!

Related benchmarks:

regex vs indexOf (version: 0)

Comparing performance of: regex vs indexOf

Created: 8 years ago by: Guest

Jump to the latest result

regex

indexOf

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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