Benchmark: String concatenation vs array join 2

Tests:

string concatention
let str = ""; const sArr = []; const limit = 10000; for (let i = 0; i < limit; i++) { str += "String concatenation. "; }
Array join
let str = ""; const sArr = []; const limit = 10000; for (let i = 0; i < limit; i++) { sArr[i] = "String concatenation. "; } str = sArr.join("");
Array join with push
let str = ""; const sArr = []; const limit = 10000; for (let i = 0; i < limit; 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 concatention
Array join
Array join with push

Fastest: N/A

Slowest: N/A

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

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Let's break down the benchmark and explain what is tested, the different approaches compared, their pros and cons, and other considerations.

**What is being tested?**

The benchmark tests three different ways to concatenate strings in JavaScript:

1. String concatenation using the `+=` operator (`"String concatenation."`)
2. Using the `join()` method on an array of strings (`sArr.join("")`)
3. Using the `push()` method to add elements to an array and then joining it with `join()` (`sArr.push("String concatenation.").join("")`)

**Approaches compared**

The three approaches are compared in terms of performance, which is measured by the number of executions per second.

**Pros and Cons of each approach:**

1. **String Concatenation using `+=` operator**
	* Pros:
		+ Simple and straightforward
		+ No need to create an array or worry about its length
	* Cons:
		+ Slow for large strings due to the overhead of creating a new string object on each iteration
		+ Can lead to memory issues if not used carefully (e.g., using `+=` in a loop without clearing the previous string)
2. **Using `join()` method on an array of strings**
	* Pros:
		+ Faster than concatenation using `+=` operator for large arrays
		+ More efficient because it avoids creating intermediate string objects
	* Cons:
		+ Requires creating an array and storing all the strings, which can be memory-intensive
		+ Less flexible than other approaches (e.g., cannot easily insert or remove elements from the middle of the string)
3. **Using `push()` method to add elements to an array and then joining it with `join()`**
	* Pros:
		+ Can be more efficient than concatenation using `+=` operator for large arrays
		+ More flexible than using `join()` alone (e.g., can insert or remove elements from the middle of the string)
	* Cons:
		+ Requires creating an array and storing all the strings, which can be memory-intensive
		+ May lead to performance issues if not used carefully (e.g., pushing many elements onto the array in a single iteration)

**Other considerations**

* Memory usage: Creating large arrays or strings can consume significant amounts of memory.
* Cache locality: The way data is stored in memory can affect performance. For example, concatenating strings using `+=` operator can lead to poor cache locality due to frequent relocations of the string object.
* Browser-specific optimizations: Different browsers may optimize their implementations of these methods differently.

**Library usage**

None of the benchmark scripts use any external libraries or frameworks. The test code only uses built-in JavaScript features and operators.

**Special JS feature/syntax**

No special JavaScript features or syntax are used in this benchmark. The code is written in standard JavaScript, using modern syntax and features (e.g., arrow functions, template literals) where applicable.

**Alternatives**

Other alternatives for string concatenation include:

1. Using a `StringBuilder` object (not available in standard JavaScript)
2. Creating a `StringBuffer` class to mimic the behavior of a `StringBuilder` object
3. Using a library like Lodash or Underscore.js, which provide utility functions for string manipulation and array operations.
4. Utilizing newer features like `Text` API or `DOMString` manipulation APIs in some browsers.

Note that these alternatives may have different performance characteristics compared to the standard JavaScript approaches tested in this benchmark.

Related benchmarks:

String concatenation vs array join 2 (version: 0)

Comparing performance of: string concatention vs Array join vs Array join with push

Created: 5 years ago by: Guest

Jump to the latest result

string concatention

Array join

Array join with push

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):