Benchmark: json stringify vs array join with string template

Script Preparation code:

function moreData(arr, left) {
  if(left === 0) return arr;
  else {
    arr.push(Math.floor(Math.random() * 256));
  	return moreData(arr, left - 1);
  }
}
function makeTestData() { return moreData([], 4); }

var data = makeTestData()

Tests:

join
`[${data.join()}]`
JSON.stringify
JSON.stringify(data);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
join
JSON.stringify

Fastest: N/A

Slowest: N/A

Latest 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.

The provided benchmark compares two approaches to concatenate an array into a string: using `Array.prototype.join()` and `JSON.stringify()`. Let's break down each approach, their pros and cons, and other considerations.

**Approach 1: Array.prototype.join()**

`join()` is a built-in JavaScript method that concatenates all elements of an array into a single string. It uses the `+` operator to concatenate the strings and iterates over the array to build the result.

Pros:

* Efficient for small arrays, as it avoids creating intermediate strings.
* Easy to read and write, with a straightforward syntax.

Cons:

* May create intermediate strings when dealing with large arrays, leading to increased memory usage.
* Not suitable for very large datasets due to performance overhead.

Other considerations:

* The `join()` method returns a new string, so it doesn't modify the original array.
* If you need to concatenate multiple arrays, you'll need to call `join()` separately for each one.

**Approach 2: JSON.stringify()**

`JSON.stringify()` is a built-in JavaScript method that converts an object or value into a JSON string. When used with an array, it will attempt to serialize the array into a string, which can be quite verbose and inefficient.

Pros:

* Can handle complex data structures, including arrays of objects.
* Returns a compact representation of the data as a string.

Cons:

* Inefficient for simple array concatenation, as it creates multiple intermediate strings.
* May not work well with large datasets or high-performance requirements.
* Less readable than `join()`, due to its verbosity.

Other considerations:

* The resulting JSON string may not be human-readable without additional processing (e.g., using a parser).
* `JSON.stringify()` is designed for serialization, not concatenation.

**Library usage**

In the benchmark, no libraries are explicitly mentioned. However, it's worth noting that if you were to use a library like Lodash or Underscore.js to concatenate arrays, the performance characteristics would likely be similar to those of `join()`. These libraries provide optimized implementation for array manipulation and concatenation.

**Special JS feature**

The benchmark doesn't appear to utilize any special JavaScript features or syntax. The code focuses on comparing two fundamental approaches to concatenating an array into a string.

Now, let's look at the provided benchmark result:

* Firefox 114 (Desktop, Mac OS X 10.15) executes `join()` approximately 18 times faster than `JSON.stringify()`, with an average of 16920064 executions per second compared to 9187871 for `JSON.stringify()`.
* The results suggest that for simple array concatenation, `join()` is the more efficient and suitable choice.

Other alternatives:

If you need alternative approaches to concatenate arrays, consider the following options:

* Using a custom implementation with optimized loops or buffers.
* Leveraging modern JavaScript features like `flatMap()` (ES6+) or `flatMap()` (ES7+).
* Utilizing third-party libraries or frameworks for array manipulation and concatenation.

Keep in mind that performance optimizations often depend on specific requirements, such as performance-critical code paths, memory constraints, or readability concerns.

Related benchmarks:

json stringify vs array join with string template (version: 0)

Comparing performance of: join vs JSON.stringify

Created: 2 years ago by: Guest

Jump to the latest result

join

JSON.stringify

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):