Benchmark: String concatenation vs array join Chrome

Script Preparation code:

var str = "";
var i;
var sArr = [];

Tests:

String concatentation
str = ''; for (i = 100; i > 0; i--) { str += "String concatenation. "; }
Array join
sArr = []; for (i = 100; i > 0; i--) { sArr[i] = "String concatenation. "; } str = sArr.join("");
Array join (w/ push)
sArr = []; for (i = 100; i > 0; i--) { sArr.push("String concatenation. "); } str = sArr.join("");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String concatentation
Array join
Array join (w/ push)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
String concatentation	119508.1 Ops/sec
Array join	222323.5 Ops/sec
Array join (w/ push)	216825.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and benchmark.

**Benchmark Definition**

The benchmark is called "String concatenation vs array join Chrome". This means we're comparing three different approaches to concatenate strings in JavaScript, specifically within the context of Google Chrome:

1. **String Concatenation**: Directly using the `+` operator to concatenate two or more strings.
2. **Array Join**: Using the `join()` method on an array of strings, where each string is a concatenation of "String concatenation. ".
3. **Array Join with Push**: Similar to Array Join, but using the `push()` method to add elements to an array instead.

**Options Compared**

The three options are compared in terms of their performance, measured by the number of executions per second.

**Pros and Cons of Each Approach:**

* **String Concatenation**:
	+ Pros: Simple and easy to read. No extra memory allocation is required.
	+ Cons: Can lead to inefficient use of memory if done repeatedly, as each concatenation creates a new string object in the DOM (in web browsers).
* **Array Join**:
	+ Pros: More efficient than String Concatenation, especially for large strings, since it avoids creating multiple string objects. It also allows for easy modification and iteration.
	+ Cons: Requires extra memory allocation for the array and its contents. The `join()` method is a DOM-specific function, which may incur additional overhead.
* **Array Join with Push**:
	+ Pros: Similar to Array Join but uses `push()` instead of `join()`, which might be seen as more " native" or efficient in some environments.
	+ Cons: May still require extra memory allocation for the array and its contents, although the impact is likely minimal.

**Library Used**

The benchmark appears to use no external libraries, relying solely on JavaScript's built-in functionality.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes used in this benchmark. It only employs basic JavaScript concepts like loops, string concatenation, and array manipulation.

**Other Considerations**

When considering these benchmarks, you should also take into account the following:

* Cache performance: Web browsers have caches that can impact execution times for repeated iterations.
* Garbage collection: Repeatedly creating and destroying strings or arrays can trigger garbage collection cycles, which might introduce overhead.
* Browser-specific optimizations: Different browsers may optimize string concatenation differently due to their own internal implementation details.

**Alternatives**

Some alternative benchmarks you could create using MeasureThat.net include:

* **String Interpolation**: Compare the performance of string interpolation (`${expression}`) with plain string concatenation or template literals.
* **Array Operations**: Benchmark different array operations like `map()`, `filter()`, and `reduce()` to determine their relative efficiency.
* **Object Creation**: Compare the creation of objects using `new Object()` versus `{ key: value }` syntax.

These benchmarks can help you better understand how JavaScript engines optimize string and array manipulation, as well as provide insights into potential performance bottlenecks in your code.

Related benchmarks:

String concatenation vs array join Chrome (version: 0)

Comparing performance of: String concatentation vs Array join vs Array join (w/ push)

Created: 4 months ago by: Guest

Jump to the latest result

String concatentation

Array join

Array join (w/ push)

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):