Benchmark: toString vs concatenation

Script Preparation code:

var obj={
  one: 'one',
  two: 'two',
  three: 'three',
  toString: () => {
    out="";
    for (var s in this)
    {
      if (typeof s == 'string')
      {
        out+=s
      }
      else
      {
        out+=s.toString()
      }
    }
  }
}

Tests:

toString
obj.toString();
concatenation
obj+"";

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toString
concatenation

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; FreeBSD amd64; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Browser/OS: Chrome 83 on FreeBSD

View result in a separate tab

Test name	Executions per second
toString	115115.4 Ops/sec
concatenation	113340.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data to understand what is being tested.

**Benchmark Definition**

The benchmark defines two approaches: `toString` and `concatenation`. Both approaches are designed to concatenate strings from an object.

**What is tested**

In this benchmark, we're comparing how two different approaches handle string concatenation:

1.  **`toString()` method**: This approach uses the built-in `toString()` method on objects. It iterates over the object's properties (using `for...in`) and checks if each property is a string. If it is, the value of that property is concatenated to the output string. Non-string values are converted to strings using their own `toString()` methods.
2.  **Concatenation with the `+` operator**: This approach uses the standard JavaScript concatenation syntax: adding two strings together.

**Pros and Cons**

### toString() method

Pros:

*   **Performance**: The `toString()` method is likely optimized for performance, as it's a built-in feature of the JavaScript engine.
*   **Consistency**: Using `toString()` ensures consistency in how non-string values are converted to strings.

Cons:

*   **Complexity**: The implementation can be complex due to its reliance on object iteration and property checking.

### Concatenation with the + operator

Pros:

*   **Simplicity**: This approach is straightforward and easy to understand.
*   **Flexibility**: It allows for more control over string concatenation, as you can use any compatible value.

Cons:

*   **Performance overhead**: The `+` operator may introduce performance overhead due to the creation of intermediate strings or unnecessary conversions.

**Library usage**

There doesn't appear to be any external libraries used in this benchmark. However, some browsers (like Chrome) might leverage internal optimizations or built-in features that aren't immediately apparent.

**Special JavaScript feature or syntax**

None of the provided code uses special JavaScript features like `async/await`, `let` constants, or ES6 classes. The implementation focuses on string concatenation and object iteration.

**Alternatives**

Some alternative approaches for string concatenation include:

*   **`String.prototype.concat()`**: A method that concatenates multiple strings together.
*   **Template literals**: Introduced in ECMAScript 2015 (ES6), template literals provide a more modern and expressive way to concatenate strings.
*   **Array methods**: Some array methods, like `join()`, can be used for string concatenation.

Keep in mind that these alternatives may have different performance characteristics or use cases compared to the original implementations.

Related benchmarks:

toString vs concatenation (version: 0)

Comparing performance of: toString vs concatenation

Created: 4 years ago by: Registered User

Jump to the latest result

toString

concatenation

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):