Benchmark: string concat vs .toString()

Tests:

String()
let num = 500; let nums = []; for(let i = 0; i < 100; ++i) { nums.push(num+''); }
.toString()
let num = 500; let nums = []; for(let i = 0; i < 100; ++i) { nums.push(num.toString()); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String()
.toString()

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/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
String()	5139344.0 Ops/sec
.toString()	1516883.1 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and analyzed.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark on MeasureThat.net. The benchmark compares two approaches to concatenate strings: using the `+` operator (string concatenation) versus calling the `.toString()` method.

**Test Cases**

There are two test cases:

1. **String()**: This test case uses string concatenation to build an array of 100 strings, each containing the number 500.
2. **.toString()**: This test case also builds an array of 100 strings, but it calls the `.toString()` method on the number 500 instead of using string concatenation.

**Comparison**

The benchmark compares the performance of these two approaches:

* **String Concatenation (String())**: This approach uses the `+` operator to concatenate strings. For example: `num + ''`.
* **.toString() Method (.toString())**: This approach calls the `.toString()` method on the number 500, which returns a string representation of the number: `500.toString()`.

**Pros and Cons**

Here's a brief analysis of each approach:

* **String Concatenation (String())**:
	+ Pros: Simple to implement and understand.
	+ Cons: Can be slower due to the overhead of creating a new string object on each concatenation.
* **.toString() Method (.toString())**: 
	+ Pros: Typically faster than string concatenation because it uses a pre-built method that optimizes string creation.
	+ Cons: Requires calling an additional method, which can introduce overhead.

**Library and Special Features**

Neither test case uses any external libraries or special JavaScript features beyond the standard `String` type and basic syntax. The `.toString()` method is a built-in method on the `Number` type that returns a string representation of the number.

**Other Alternatives**

If you wanted to modify this benchmark, here are some alternative approaches you could consider:

* Using a different concatenation approach, such as using an array's `push` method with a template literal (e.g., `[...nums, num]`) or using a library like Lodash's `repeat` function.
* Adding additional test cases that compare other string manipulation techniques, such as using `slice()` or `substring()`.
* Using different input values, such as larger numbers or strings, to see how the benchmark performs under varying conditions.

I hope this explanation helps!

Related benchmarks:

string concat vs .toString() (version: 0)

Comparing performance of: String() vs .toString()

Created: one year ago by: Guest

Jump to the latest result

String()

.toString()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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