Benchmark: String.replace vs String.slice

Tests:

String.replace
'2xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'.replace('2', '');
String.slice
'2xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'.slice(1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.replace
String.slice

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 Edg/107.0.1418.35

Browser/OS: Chrome 107 on Windows

View result in a separate tab

Test name	Executions per second
String.replace	10336770.0 Ops/sec
String.slice	676251392.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided JSON represents a benchmark test that compares the performance of two different approaches for replacing a character in a string: `String.replace` and `String.slice`. The test aims to measure which method is faster, especially when dealing with large strings like the one defined in the first benchmark definition: `'2xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'`.

**Options being compared:**

1. **String.replace**: This method replaces all occurrences of a specified character (in this case, '2') with an empty string (`''`). It's a built-in JavaScript method that returns a new string.
2. **String.slice**: This method extracts a section of a string and returns it as a new string. In the first test case, it slices off the first character by passing `1` as the starting index.

**Pros and cons:**

* **String.replace**:
	+ Pros:
		- More concise and readable code.
		- Less CPU-intensive since it doesn't require looping through the entire string.
	+ Cons:
		- May be slower due to the overhead of regular expression processing (depending on the implementation).
		- Can consume more memory if dealing with very large strings.
* **String.slice**:
	+ Pros:
		- Faster and more lightweight since it only requires a simple array operation.
		- More memory-efficient, as it doesn't create a new string object.
	+ Cons:
		- Less readable code due to the index-based approach.
		- Requires looping through the entire string to extract the desired section.

**Library usage:**

In this test case, there is no explicit library usage. However, MeasureThat.net might use internal libraries or frameworks for benchmarking and execution.

**Special JavaScript feature/syntax:**

There are no special JavaScript features or syntax used in this test case that would require additional explanation.

Now, let's take a look at the latest benchmark results:

The results show that **String.slice** is significantly faster than **String.replace**, with an execution rate of approximately 10336770.0 executions per second compared to 676251392.0 for **String.replace**. This suggests that `String.slice` is indeed the more efficient approach when dealing with large strings.

**Other alternatives:**

If you're looking for alternative approaches, here are a few options:

1. **Using a regex replacement**: You could use the `replace()` method with a regular expression to achieve the same result as `String.replace`. However, this would likely be slower due to the overhead of regex processing.
2. **Using a loop**: Instead of using `String.replace` or `String.slice`, you could write a simple loop that iterates over each character in the string and replaces it manually. This approach would likely be the slowest due to the manual iteration and potential for errors.

Keep in mind that these alternatives are not recommended unless you have specific requirements or constraints that necessitate their use.

I hope this explanation helps!

Related benchmarks:

String.replace vs String.slice (version: 0)

Check the speed of replacing the first character via String.replace vs String.slice

Comparing performance of: String.replace vs String.slice

Created: 5 years ago by: Guest

Jump to the latest result

String.replace

String.slice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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