Benchmark: propert access - MeasureThat.net

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

let obj = {a:3}

Tests:

dot
for(let i = 1337;i--;)obj.a+=1
bracket
for(let i = 1337;i--;)obj['a']+=1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
dot
bracket

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; CrOS x86_64 14695.114.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36

Browser/OS: Chrome 102 on Chrome OS 14695.114.0

View result in a separate tab

Test name	Executions per second
dot	73361.4 Ops/sec
bracket	67246.1 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided benchmark is focused on measuring the performance of property access methods in JavaScript objects. Specifically, it compares two ways to access properties of an object: using dot notation and bracket notation.

### Benchmark Overview

- **Benchmark Name**: Property access
- **Preparation Code**: The benchmark prepares an object `obj` with a property `a` initialized to `3`. This serves as a common reference point for both types of property access being tested.

### Test Cases

The individual test cases perform the same operation (incrementing the value of `obj.a`) but access the property in different ways:

1. **Dot Notation**:
   - **Benchmark Definition**: `for(let i = 1337;i--;)obj.a += 1`
   - **Test Name**: "dot"
   - **Description**: This test accesses the `a` property of the `obj` using dot notation. Dot notation is the simpler and more commonly used method for accessing properties when the property name is known and is a valid identifier.

2. **Bracket Notation**:
   - **Benchmark Definition**: `for(let i = 1337;i--;)obj['a'] += 1`
   - **Test Name**: "bracket"
   - **Description**: This test accesses the property `a` using bracket notation. Bracket notation allows for the property name to be specified as a string, which is useful for dynamically accessing properties or when property names contain special characters or spaces.

### Performance Results

The latest benchmark result shows the performance in terms of "executions per second" for each test case:

- **Dot Notation**: ~73361 operations/second
- **Bracket Notation**: ~67246 operations/second

### Comparison of Approaches

#### Pros and Cons

- **Dot Notation**:
  - **Pros**:
    - More concise and readable.
    - Generally faster in most environments due to simpler parsing.
  - **Cons**:
    - Cannot be used for property names that are not valid identifiers (e.g., containing spaces, special characters, or starting with a number).

- **Bracket Notation**:
  - **Pros**:
    - More flexible – can reference properties with names that are not valid identifiers.
    - Useful for dynamic property access (e.g., `obj[propertyName]`).
  - **Cons**:
    - Slightly less readable in many cases.
    - May incur a performance hit compared to dot notation, as seen in the benchmark results.

### Other Considerations

- In the benchmark tests, both methods are simple and straightforward; thus, performance differences may be negligible in many real-world scenarios where property access does not represent a performance bottleneck.
- For large applications, ensuring that object property access is efficient can be important, especially in performance-critical code paths (e.g., game loops, real-time data processing).

### Alternatives

While the benchmark focuses specifically on dot and bracket notations for property access, it is worth noting that other alternatives for managing object properties include:

- **Object.defineProperty()**: Allows defining a property with custom attributes (getter/setter, enumerable, configurable). This can be useful for creating more controlled access patterns but is typically slower and more complex than direct access.
- **Proxies**: Introduced in ES6, Proxies allow for the creation of a handler object that can redefine fundamental operations on objects, including property access. However, performance may vary based on implementation and use-case.

In summary, this benchmark provides clarity on the performance implications of different property access methods in JavaScript, valuable information for developers aiming to write efficient and effective code.

Related benchmarks:

propert access (version: 1)

Comparing performance of: dot vs bracket

Created: one year ago by: Guest

Jump to the latest result

dot

bracket

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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