Benchmark: string + vs concat

Script Preparation code:

var str = "";
for (var i = 65534; i > 0; i--) str.concat(String(i));for (var i = 65534; i > 0; i--) str.concat(String(i));

Tests:

+
var str = ""; for (var i = 65534; i > 0; i--) str += String(i);
concat
var str = ""; for (var i = 65534; i > 0; i--) str.concat(String(i));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
+
concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
+	216.4 Ops/sec
concat	227.7 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark analysis.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark that tests two approaches for creating strings: using the `+=` operator and the `concat()` method.

**Options Compared**

Two options are being compared:

1. **Using `+=` operator**: This approach involves concatenating strings using the `+=` operator. The script preparation code creates an initial string `str` and then repeatedly appends numbers to it using `str += String(i)`.
2. **Using `concat()` method**: This approach uses the `concat()` method to concatenate strings. The script preparation code also creates an initial string `str`, but this time it uses `str.concat(String(i))` to append numbers.

**Pros and Cons**

* **Using `+=` operator:**
	+ Pros:
		- Efficient in terms of memory allocation, as a new string object is created only when the concatenation operation is performed.
	+ Cons:
		- May lead to slower performance due to the repeated use of the `+=` operator, which involves creating and assigning a new value.
* **Using `concat()` method:**
	+ Pros:
		- More efficient than using the `+=` operator for large strings, as it avoids creating multiple intermediate string objects.
	+ Cons:
		- May lead to slower performance due to the overhead of calling the `concat()` method repeatedly.

**Library Usage**

There is no explicit library usage in this benchmark. However, some JavaScript engines may use internal libraries or optimized implementations that might affect the results.

**Special JS Feature/Syntax**

The benchmark uses a syntax feature specific to JavaScript: the `for` loop with an incrementing variable (`i`). This is not unique to JavaScript and can be found in many programming languages.

**Benchmark Preparation Code**

The script preparation code creates an initial string `str` and then appends numbers to it using either the `+=` operator or the `concat()` method. The numbers are generated using a loop that starts from 65534 and decrements until 0.

**Other Alternatives**

If you wanted to test this benchmark on other programming languages, you could consider alternatives like:

1. **C++**: You can use a C++ compiler like GCC or Clang to compile a C++ program that performs the same concatenation operations.
2. **Java**: You can write a Java program using a for loop and string concatenation to test the performance of this benchmark on the Java Virtual Machine (JVM).
3. **C#**: You can use a C# compiler like Mono or .NET Core to compile a C# program that performs the same concatenation operations.

Keep in mind that each language has its own nuances, optimizations, and caching mechanisms, which may affect the results of this benchmark.

In terms of JavaScript engines specifically, you could consider testing this benchmark on:

1. **V8**: The default engine for Google Chrome.
2. **SpiderMonkey**: The default engine for Mozilla Firefox.
3. **Chakra**: The default engine for Microsoft Edge.

These engines have different optimization strategies, caching mechanisms, and features that may impact the performance of this benchmark.

Related benchmarks:

string + vs concat (version: 0)

Comparing performance of: + vs concat

Created: 2 years ago by: Guest

Jump to the latest result

+

concat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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