Benchmark: string character comparison for...of vs for loop

Script Preparation code:

var str = ''
for(let i = 0;i<10000; i++) {
  str+=(Math.random()<.5?'a':'b')
}
var deleted = 0

Tests:

for loop
for(let i=0;i<str.length;i++){ if(str[i] === str[i+1]) deleted++ } return deleted
for of
var last = '' for(let i of str){ if(i === last) deleted++ last = i } return deleted

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
for of

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark measures the performance difference between two approaches: traditional `for` loops and the newer `for...of` loop syntax. Both loops are used to compare each character in a string with its adjacent characters, incrementing a counter if a match is found.

**Script Preparation Code**

The script preparation code generates a string of 10,000 random characters (either 'a' or 'b') using the `Math.random()` function. This creates a large, seemingly random dataset that's perfect for testing performance differences between loops.

**Options Compared**

Two options are being compared:

1. **Traditional `for` loop**: A traditional `for` loop is used to iterate over the characters in the string.
2. **`for...of` loop**: The newer `for...of` loop syntax is used, which is a more concise and expressive way of iterating over arrays or iterables.

**Pros and Cons**

Here are some pros and cons of each approach:

Traditional `for` loop:

Pros:

* Widely supported across older browsers
* Easy to understand for developers familiar with traditional loops

Cons:

* Can be verbose, especially when dealing with large datasets
* May have slower performance compared to `for...of`

`for...of` loop:

Pros:

* More concise and expressive than traditional `for` loops
* Better suited for iterating over arrays or iterables

Cons:

* Less widely supported across older browsers (although still supported in modern versions)
* Can be less intuitive for developers unfamiliar with the syntax

**Library Used**

In both benchmark scripts, the `deleted` variable is used to store the count of consecutive matches. There's no explicit library used here, as it's just a simple counter.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark, such as async/await, promises, or arrow functions. The focus is solely on comparing the performance of two iteration approaches.

**Other Alternatives**

If you're interested in exploring other microbenchmarking options, here are a few alternatives:

1. **Benchmark.js**: A lightweight JavaScript library for writing and running benchmarks.
2. **Benchmarklib**: A benchmarking framework that provides a simple way to write and compare benchmarks.
3. **Google Benchmark**: A high-performance benchmarking tool designed specifically for testing performance-critical code.

Remember, when choosing a microbenchmarking tool or approach, consider factors such as accuracy, reliability, and the specific use case you're trying to measure.

Related benchmarks:

string character comparison for...of vs for loop (version: 0)

Testing different between loops

Comparing performance of: for loop vs for of

Created: 3 years ago by: Guest

Jump to the latest result

for loop

for of

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):