Benchmark: stringbuilder - MeasureThat.net

Tests:

join
const arr = [] for (let i=0; i<100000; i++) { arr.push('a' + i) } console.log(arr.join(''))
concatenate
let b = '' for (let i=0; i<100000; i++) { b += 'a' + i } console.log(b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
join
concatenate

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Safari/605.1.15

Browser/OS: Safari 17 on Linux

View result in a separate tab

Test name	Executions per second
join	11.7 Ops/sec
concatenate	21.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmarking test cases and explain what's being tested, compared, and the pros/cons of each approach.

**Benchmark Definition**

The JSON object representing the benchmark contains the following properties:

* `Name`: The name of the benchmark, which is "stringbuilder".
* `Description`: An empty string, indicating that no description is provided for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: Empty strings, suggesting that no script or HTML preparation code needs to be executed before running the benchmark.

**Individual Test Cases**

The benchmark consists of two individual test cases:

1. **"join"`**
```javascript
const arr = []
for (let i=0; i<100000; i++) {
  arr.push('a' + i)
}
console.log(arr.join(''))
```
This test case creates an array `arr` with 100,000 elements and then logs the result of calling the `join()` method on the array, concatenating all elements with a space separator.

2. **"concatenate"`**
```javascript
let b = ''
for (let i=0; i<100000; i++) {
  b += 'a' + i
}
console.log(b)
```
This test case creates an empty string `b` and then appends 100,000 elements to it using the `+=` operator.

**Comparison of Approaches**

Both approaches aim to measure the performance of concatenating strings in JavaScript. However, they differ in their approach:

* **"join()"**: This method uses a built-in array method that iterates over the elements and appends them to an internal buffer. The resulting string is then returned.
* **"concatenate"`: This approach uses a simple loop to append elements to a string.

**Pros and Cons**

**"join()"**:

Pros:

* Efficient, as it uses optimized code in the browser's engine.
* Less memory-intensive, as it doesn't require creating an array of strings.

Cons:

* May not be suitable for small arrays or strings, where the overhead of `join()` may outweigh the benefits.
* Can result in a larger final string if the elements are longer than the space separator.

**"concatenate"`:

Pros:

* Simple and easy to understand.
* Suitable for small arrays or strings.

Cons:

* Less efficient due to the loop and string concatenation, which can lead to slow performance.
* Memory-intensive, as it creates a new array of strings in memory.

**Library: `join()`**

The `join()` method is a built-in JavaScript function that concatenates elements from an array into a single string. It's optimized for performance and uses internal buffers to minimize overhead.

**Special JS Feature/Syntax**

This benchmark doesn't utilize any special JavaScript features or syntax, making it accessible to developers with varying levels of expertise.

**Alternatives**

If you're looking for alternative approaches or have specific requirements, consider the following:

1. **Use a different string concatenation method**: You could use `Array.prototype.map()` and `Array.prototype.join()`, which can be more efficient for large arrays.
2. **Use a library like Lodash**: Lodash provides an optimized `join()` function that can be used instead of the built-in one.
3. **Optimize for small strings**: If you're working with very short strings, you might consider using a simpler approach like string concatenation or even using a fixed-width string format to reduce overhead.

Keep in mind that benchmarking JavaScript performance can be complex and dependent on various factors, such as the browser engine, platform, and hardware.

Related benchmarks:

stringbuilder (version: 0)

Comparing performance of: join vs concatenate

Created: one year ago by: Guest

Jump to the latest result

join

concatenate

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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