Benchmark: String concatenation vs array join Chrome 3

Script Preparation code:

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

Tests:

String concatentation
str = ''; for (i = 1000; i > 0; i--) { str += "String concatenation. " + i; }
Array join
sArr = []; for (i = 1000; i > 0; i--) { sArr[i] = "String concatenation. " + i; } str = sArr.join("");
Array join (w/ push)
sArr = []; for (i = 1000; i > 0; i--) { sArr.push("String concatenation. " + i); } 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: one year 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	11523.9 Ops/sec
Array join	18889.7 Ops/sec
Array join (w/ push)	18535.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark.

**What is being tested?**

The benchmark measures the performance of two approaches to concatenate strings:

1. **String concatenation**: This involves using the `+` operator to concatenate strings in a loop (in this case, 1000 iterations).
2. **Array join**: This approach uses an array to store strings and then joins them together using the `join()` method.

**Options compared**

The benchmark compares three variants of the Array join approach:

1. **Basic Array join**: Uses `sArr.join("")` to concatenate the strings in the array.
2. **Array join with push**: Uses `push()` to add strings to the array and then uses `join()` to concatenate them.

**Pros and Cons**

Here are some pros and cons of each approach:

* **String concatenation**:
	+ Pros: Simple and easy to understand, no extra memory allocation required.
	+ Cons: Can be slow due to the overhead of creating a new string object in each iteration.
* **Basic Array join**:
	+ Pros: Can be faster than string concatenation because it avoids the overhead of creating multiple string objects.
	+ Cons: Requires an array to store all strings, which can lead to higher memory usage.
* **Array join with push**:
	+ Pros: Combines the benefits of basic array join and string concatenation (avoiding memory allocation).
	+ Cons: Still requires some memory allocation for the array.

**Other considerations**

The benchmark does not consider other factors that might affect performance, such as:

* Optimizations for modern browsers
* Differences in browser engines or implementations
* Impact of code organization or caching on performance

**Library and syntax**

There is no explicit library mentioned in the benchmark definition. However, the `join()` method is a built-in JavaScript method used to concatenate strings.

No special JavaScript features or syntax are being tested in this benchmark.

**Alternatives**

If you want to explore other approaches to string concatenation or array join, consider:

* Using `template literals` (introduced in ECMAScript 2015) for simple concatenation.
* Utilizing `concat()` method on arrays for joining strings.
* Investigating third-party libraries like Lodash for functional programming utilities.

Note that these alternatives may not be relevant to the specific performance comparison being made here.

Related benchmarks:

String concatenation vs array join Chrome 3 (version: 0)

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

Created: one year ago by: Guest

Jump to the latest result

String concatentation

Array join

Array join (w/ push)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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