Benchmark: String concatenate vs array join

Tests:

string concatenate
let obj = {} for(let i = 0; i < 1000; i++) { obj["a"+i] = 0 } let columns = "" for(let y in obj) { columns += (y + ", ") } columns = "(" + columns.slice(0, -2) + ")"
array join
let obj = {} for(let i = 0; i < 1000; i++) { obj["a"+i] = 0 } let columns = Object.keys(obj).join(", ")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
string concatenate
array join

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Linux; Android 11; SM-G973F) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.86 Mobile Safari/537.36

Browser/OS: Chrome Mobile 89 on Android

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Test name	Executions per second
string concatenate	3976.5 Ops/sec
array join	4512.3 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided JSON represents two microbenchmarks for measuring the performance of string concatenation versus array join in JavaScript.

**Benchmark Options**

There are two approaches being compared:

1. **String Concatenation**: This method involves using the `+` operator to concatenate strings, as seen in the first benchmark definition: `"columns += (y + ", ")"`
2. **Array Join**: This method uses the `join()` function on an array of strings, as seen in the second benchmark definition: `obj.keys().join(", ")`

**Pros and Cons**

**String Concatenation**

Pros:

* Easy to read and write
* Does not require additional data structures (like arrays)

Cons:

* Can be slow for large numbers of concatenations due to the overhead of creating temporary strings
* May lead to unexpected performance issues if not used carefully

**Array Join**

Pros:

* Can be faster than string concatenation, especially for large datasets, since it avoids the creation of temporary strings
* More efficient in terms of memory usage

Cons:

* Requires additional data structure (the array), which can increase memory overhead
* May have higher overhead due to function call and iteration

**Library and Features**

In both benchmark definitions, no specific libraries are used. However, note that `Object.keys()` is a built-in JavaScript method that returns an array-like object containing the enumerable properties of the specified object.

**Special JS Features or Syntax**

There's nothing special about the syntax in these benchmark definitions. They are straightforward examples of string concatenation and array join.

**Other Alternatives**

Some alternative approaches to array join could be:

* Using a `Set` instead of an array, since `Set` has faster lookup times
* Using a `Map` instead of an object, since `Map` provides faster iteration
* Using a library like Lodash's `join()` function or a custom implementation using a more efficient data structure

However, it's worth noting that the choice of approach depends on the specific requirements and constraints of the use case.

**Benchmark Preparation Code**

The provided "Script Preparation Code" is empty, which means that no additional setup code is required before running the benchmarks. The HTML preparation code is also empty, suggesting that no custom HTML setup is necessary.

Keep in mind that these are just general explanations, and actual performance results may vary depending on the specific use case, hardware, and environment.

Related benchmarks:

String concatenate vs array join (version: 0)

Comparing performance of: string concatenate vs array join

Created: 3 years ago by: Guest

Jump to the latest result

string concatenate

array join

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):