Benchmark: str.match vs str.Split and for each

Script Preparation code:

string = "This is a benchmark to test if matching a regex is faster that splitting a string";
regex = /\S+/gi;

Tests:

String.split
string.split("").forEach(p => console.log(p))
Regex.match
string.match(regex)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.split
Regex.match

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Definition**

The benchmark is comparing the performance of two approaches:

1. **`string.match(regex)`**: This method uses regular expressions to search for a pattern in a string. In this case, the regex `/\\S+/gi` matches one or more non-space characters ( `\S+` ) globally ( `g` flag) and ignores case ( `i` flag).
2. **`string.split(\"\").forEach(p => console.log(p))`**: This method splits a string into an array of substrings using spaces as separators and then iterates over the array, logging each substring to the console.

**Options Compared**

The benchmark is comparing these two approaches:

* `string.match(regex)` vs. `string.split(\"\").forEach(p => console.log(p))`
* The order of operations: matching a regex against a string versus splitting a string and then iterating over its parts

**Pros and Cons**

Here's a brief analysis of the pros and cons of each approach:

**`string.match(regex)`**

Pros:

* Can be faster for simple cases, as it uses a single pass through the input string.
* Allows for more control over the matching process.

Cons:

* May not work correctly if the regex pattern is complex or requires multiple passes through the input string.
* Can lead to performance issues if the regex pattern is too broad or has a high computational complexity.

**`string.split(\"\").forEach(p => console.log(p))`**

Pros:

* Generally more straightforward and easier to understand for simple use cases.
* Allows for iteration over the resulting parts of the split string.

Cons:

* May be slower due to the overhead of creating an array and iterating over it.
* Requires additional memory allocation.

**Other Considerations**

In this benchmark, we can also consider other factors that might influence performance, such as:

* **Memory Allocation**: Both approaches require some memory allocation, but `string.match(regex)` might have a slight advantage in terms of minimal memory usage compared to the array created by `string.split(\"\").forEach(p => console.log(p))`.
* **Cache Locality**: The order of operations can affect cache locality, which may impact performance. For example, if the regex pattern is large and spans multiple passes through the input string, this might lead to more memory accesses and slower performance.

**Library**

In this benchmark, there's no explicit mention of a JavaScript library being used beyond the built-in `String` and `RegExp` objects.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in this benchmark. It appears to be using standard JavaScript language features.

Now, let's take a look at the individual test cases:

1. **`string.split(\"\").forEach(p => console.log(p))`**: This test case simply creates an array by splitting a string into substrings and then iterates over the resulting parts.
2. **`string.match(regex)`**: This test case uses a regex pattern to search for a match in a string.

The latest benchmark results show that `Regex.match` is significantly faster than `String.split` with a factor of approximately 1000x.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/118.0

Browser/OS: Firefox 118 on Windows

View result in a separate tab

Test name	Executions per second
String.split	1974.2 Ops/sec
Regex.match	1667598.2 Ops/sec

Related benchmarks:

str.match vs str.Split and for each (version: 0)

Test String.match with regex against String.split with string. We are splitting a string at the spaces.

Comparing performance of: String.split vs Regex.match

Created: one year ago by: Guest

Jump to the latest result

String.split

Regex.match

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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