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

Benchmark Description

The provided benchmark measures the performance difference between two string replacement methods: replace() and replaceAll(). These methods are used to replace occurrences of a pattern in a string.

Options Compared

There are only two options being compared:

1. replace(): This method uses regular expressions (regex) to find and replace patterns in a string. It returns the modified string.
2. replaceAll(): This method is not a standard JavaScript method, but rather a proprietary method used by some JavaScript engines, including Firefox. It's similar to replace(), but with an additional option for case sensitivity.

Pros and Cons

• replace():
  • Pros: widely supported across most JavaScript engines, efficient, and concise.
  • Cons: may not be as readable or maintainable due to the use of regex patterns.
• replaceAll():
  • Pros: faster performance in some cases (as seen in the benchmark result), possibly useful for specific use cases.
  • Cons: non-standard method, may not work across all JavaScript engines, and its behavior can vary depending on the engine implementation.

Library and Syntax

Neither of these methods uses a library. Instead, they are built-in string manipulation functions in JavaScript.

Special JS Feature or Syntax

The replaceAll() method is not a standard JavaScript method, but rather a proprietary method used by some JavaScript engines, including Firefox. This means that while it may be supported by some browsers, it's not guaranteed to work across all platforms and versions.

Benchmark Preparation Code

The provided script preparation code for the benchmark is simply:

this is it.replace(/ /g, "+");

This code defines a string this is it and replaces each space character (\s) with a plus sign (+). The / /g regex pattern matches one or more whitespace characters globally.

Individual Test Cases

The benchmark has two test cases:

1. regex: This test case runs the script preparation code using the replace() method.
2. benchmark: This test case runs the same script preparation code, but uses the proprietary replaceAll() method.

Latest Benchmark Result

The latest benchmark result shows that Firefox 109 performs better with the replaceAll() method, executing approximately 43% more times per second than the replace() method on a Desktop with Linux operating system.