Benchmark: array join vs toString js vs json

Script Preparation code:

var arr = ['1',2,null,undefined,'5','6','7','8']

Tests:

join
arr.join()
toString
arr.toString()
json
JSON.stringify(arr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
join
toString
json

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 days ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Linux

View result in a separate tab

Test name	Executions per second
join	3640645.5 Ops/sec
toString	3140322.5 Ops/sec
json	2803046.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 days ago):

LLMs can make mistakes. Check important info.

The benchmark in question measures the performance of three different methods for converting an array into a string in JavaScript.

### Options Compared
1. **`arr.join()`**
2. **`arr.toString()`**
3. **`JSON.stringify(arr)`**

### Explanation of Each Method

1. **`arr.join()`**:
   - **Description**: This method concatenates all elements of an array into a single string, separated by a specified separator (default is a comma).
   - **Pros**:
     - Allows for customizable separators.
     - Generally performs well for standard use cases.
   - **Cons**:
     - Might have different performance characteristics depending on the size of the array and the separator used.

2. **`arr.toString()`**:
   - **Description**: This method converts the array to a string. Each element is converted to a string, and the elements are joined by commas.
   - **Pros**:
     - Simple and quick for concatenating elements with default behavior.
   - **Cons**:
     - Less flexible compared to `join()`, as it does not allow for a custom separator.

3. **`JSON.stringify(arr)`**:
   - **Description**: This method converts a JavaScript object or value to a JSON string. In the case of an array, it converts each element to JSON format.
   - **Pros**:
     - Handles objects, nested arrays, and provides a valid JSON representation.
   - **Cons**:
     - Can be slower due to additional serialization processes involved in producing a JSON string.
     - Overkill for simple array-to-string conversions where JSON formatting is not needed.

### Performance Results
According to the latest benchmark results:
- The method `arr.join()` achieved the highest performance at approximately **9,734,147.0 executions per second**.
- `JSON.stringify(arr)` followed with about **8,306,098.5 executions per second**.
- `arr.toString()` came last at around **8,038,698.5 executions per second**.

### Considerations
- **Use Case**: The choice of method depends on the specific use case. If you need a simple string representation without additional formatting, `arr.join()` or `arr.toString()` would be sufficient. If you need to serialize an array for API communication or storage, `JSON.stringify()` is the right choice.
- **Performance**: When performance is critical, especially in tight loops or heavy computations, `arr.join()` provides the best performance of the three.
- **Output Requirements**: If the output needs to adhere to a specific format (such as JSON), using `JSON.stringify()` is necessary despite its slower performance.

### Alternatives
- **Template Strings**: If constructing strings with a few elements or for complex formatting, JavaScript’s template literals could be employed (e.g., `` `${arr[0]}, ${arr[1]}, ...` ``).
- **Custom Serialization Functions**: For scenarios that demand custom formatting or conditions during string conversion, creating a dedicated serialization function could provide optimized performance or additional features.

In summary, while `arr.join()` offers the best performance for straightforward array to string conversion, `JSON.stringify()` and `arr.toString()` serve different purposes that may be more appropriate depending on the context of use.

Related benchmarks:

array join vs toString js vs json (version: 1)

test

Comparing performance of: join vs toString vs json

Created: 5 days ago by: Guest

Jump to the latest result

join

toString

json

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 5 days ago):