Benchmark: JSON.parse vs String.match for fetching one value

Script Preparation code:

var ob = `{"aenderungen":[],"_id":"64c0fc4abd2c8bd76c9553f2","name":"Maxis","geburtsdatum":"2023-08-02T00:00:00.000Z","ICD10Code":"k k k k k ","position":0,"empfangsdatum":"2023-07-26T10:58:18.716Z","hinzugefügtVon":"6498bf3b2afb897aa26d18e6","infos":{"berichte":"ggg","puls":"hallo yazn "},"positionarr":[0,0],"stationen":[],"__v":0}`

Tests:

JSON.parse()
var value = JSON.parse(ob)._id;
String.match
const value = ob.match(/"_id":"(\w+)"/)[1]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
JSON.parse()
String.match

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0

Browser/OS: Firefox 137 on Ubuntu

View result in a separate tab

Test name	Executions per second
JSON.parse()	1505912.8 Ops/sec
String.match	19744964.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark provided compares two approaches for extracting a specific value (`_id`) from a JSON-formatted string. The two methods being tested are:

1. Using `JSON.parse()`
2. Using `String.match()`

### Options Compared

1. **JSON.parse()**
   - **Benchmark Definition**: `var value = JSON.parse(ob)._id;`
   - **Description**: This method parses a JSON string and converts it into a JavaScript object, from which the `_id` property is accessed directly.
   - **Pros**:
     - It's simple and straightforward for structured data.
     - Automatically handles various types within the JSON (strings, numbers, arrays, nested objects).
   - **Cons**:
     - It requires the entire string to be parsed, which can be less efficient if only one value is needed from a very large JSON string.
     - May throw an error if the string is not valid JSON.

2. **String.match()**
   - **Benchmark Definition**: `const value = ob.match(/\"_id\":\"(\\w+)\"/)[1];`
   - **Description**: This regex-based method matches and extracts the value of `_id` directly from the string without converting the entire JSON string into an object.
   - **Pros**:
     - More efficient for extracting a specific piece of data since it doesn't have to parse the entire JSON structure.
     - Can be faster in situations where only a single value is needed.
   - **Cons**:
     - Less flexible and more prone to errors if the JSON structure changes (e.g., the key is renamed or the format is altered).
     - Less readable and maintainable, especially if the extraction logic becomes complex or is applied to more fields.

### Benchmark Results

The benchmark results indicate both methods were executed on Firefox 137 on an Ubuntu desktop platform, yielding the following performance metrics:

- **String.match**: Achieved approximately **19,744,964 executions per second**.
- **JSON.parse()**: Achieved approximately **1,505,912.75 executions per second**.

From these results, it is evident that `String.match()` is significantly faster than `JSON.parse()` for extracting the `_id` value from the string. The large difference in execution speed underlines the benefit of using regex when you only need a specific value from a larger JSON string, especially in performance-sensitive applications.

### Other Considerations

- **Error Handling**: Using `JSON.parse()` might be safer because it validates the input string as a JSON object. In contrast, `String.match()` could produce unintended results if the string is malformed or if it does not contain the expected structure.
- **Complexities**: If you anticipate needing to extract multiple values or manipulate the JSON data, `JSON.parse()` may be the better option overall, even if it is slower, as the resulting object allows more straightforward access to all properties.

### Alternatives

Other alternatives for fetching values from a JSON string could include:

1. **Using a dedicated JSON library**: Libraries such as `lodash` can provide utility functions that simplify working with JSON data.
2. **Using manual string manipulation**: This is usually less efficient and error-prone compared to regex or parsing, but can be suitable for certain cases where performance is not a critical factor.
3. **Using data-binding frameworks**: In applications where complex data manipulations are needed, frameworks such as React or Vue can handle state and updates more dynamically and efficiently.

In conclusion, while both methods have their place, the best approach depends on the context of use—whether speed or data structure integrity is more critical.

Related benchmarks:

JSON.parse vs String.match for fetching one value (version: 1)

Comparing performance of: JSON.parse() vs String.match

Created: one year ago by: Guest

Jump to the latest result

JSON.parse()

String.match

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):