Benchmark: String Concatenation

Script Preparation code:

var base = "HEY",
    a = "BOB";

Tests:

Standard Plus Concat
base = base + a;
Plus Equals
base += a;
String.Concat
base = string.concat(a, b);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Standard Plus Concat
Plus Equals
String.Concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 9_3_5 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13G36 Safari/601.1

Browser/OS: Mobile Safari 9 on iOS 9.3.5

View result in a separate tab

Test name	Executions per second
Standard Plus Concat	1935445.2 Ops/sec
Plus Equals	1792490.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the JavaScript microbenchmark on MeasureThat.net.

**Benchmark Overview**

The benchmark is designed to measure the performance of string concatenation in JavaScript. It compares three different approaches:

1. **Standard Plus Concat**: Using the `+` operator for concatenation (e.g., `base + a`)
2. **Plus Equals**: Using the `+=` assignment operator for concatenation (e.g., `base += a`)
3. **String.Concat**: Using the `concat()` method for concatenation

**Options Comparison**

Here's a brief overview of each approach:

* **Standard Plus Concat**:
	+ Pros: Widely supported and understood by most developers.
	+ Cons: Can lead to performance issues due to the creation of intermediate strings, as shown in the benchmark results.
* **Plus Equals**:
	+ Pros: Often used for concatenation, especially in situations where `base` is already assigned a value. However, this approach can lead to unnecessary reassignments and memory allocations.
	+ Cons: Can still result in performance issues due to intermediate string creation, similar to the Standard Plus Concat approach.
* **String.Concat**:
	+ Pros: Efficiently creates an array of strings without creating intermediate arrays or objects. This is particularly useful for large concatenations.
	+ Cons: Requires a supported browser and/or JavaScript engine (not all engines support it).

**Library/Functionality Consideration**

In this benchmark, the `concat()` method is used, which is a part of the ECMAScript standard and widely supported by most modern browsers. This allows users to run the benchmark on various devices without worrying about compatibility issues.

**Special JS Features/Syntax (None)**

There are no special JavaScript features or syntaxes being tested in this benchmark. The focus is solely on string concatenation using different approaches.

**Other Alternatives**

If you're looking for alternative ways to concatenate strings, consider the following:

* **Array.prototype.push()**: Concatenating strings using `push()` can lead to performance issues due to array resizing.
* **String.join()**: Using `join()` with an empty string can be more efficient than concatenation methods.
* **Template literals** (introduced in ECMAScript 2015): Template literals provide a concise and efficient way to concatenate strings without the need for explicit operator overloading.

Keep in mind that these alternatives might not be as widely supported or understood by all developers, which could affect benchmark results or code maintainability.

Related benchmarks:

String Concatenation (version: 5)

Comparing performance of: Standard Plus Concat vs Plus Equals vs String.Concat

Created: 8 years ago by: Registered User

Jump to the latest result

Standard Plus Concat

Plus Equals

String.Concat

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):