Benchmark: Object Property x Local Variable Accessing 1

Tests:

Object Property
class Bar { constructor() { this.prop = { foo: function() { } } } test() { if(this.prop.foo) { this.prop.foo() } } } const b = new Bar() b.test()
Local Variable
class Bar { constructor() { this.prop = { foo: function() { } } } test() { const foo = this.prop.foo if(foo) { foo() } } } const b = new Bar() b.test()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object Property
Local Variable

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/134.0.6998.99 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 134 on iOS 18.3.2

View result in a separate tab

Test name	Executions per second
Object Property	7882790.0 Ops/sec
Local Variable	8103683.5 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided benchmark focuses on measuring the performance of two different methods for accessing a property of an object in JavaScript. Specifically, it compares accessing a method directly through an object property versus storing that method in a local variable and then invoking it.

### Test Cases Overview:
1. **Object Property Access**: 
   - **Benchmark Definition**: Creates a class `Bar` with a property `prop` that contains a method `foo`. The `test` method checks if `this.prop.foo` exists and calls it.
   - **Performance Measurement**: Directly accesses the method through the property of the object each time.

2. **Local Variable Access**:
   - **Benchmark Definition**: Similar to the first test, but here the method `foo` is assigned to a local variable `foo`. In the `test` method, it checks if `foo` exists and calls it.
   - **Performance Measurement**: Accesses the method via the local variable instead of the object property.

### Comparison of Options:
- **Direct Object Property Access (Object Property)**:
  - **Pros**: Straightforward and clear, especially for accessing properties directly.
  - **Cons**: Each access requires a lookup on the object, which could involve additional overhead, particularly in environments with less optimized property access.

- **Local Variable Access**:
  - **Pros**: Generally faster because it only requires a single lookup at the beginning (when assigning to the local variable). Subsequent accesses to the method can be done through the local variable, which is typically faster than repeatedly looking it up on the object.
  - **Cons**: Slightly less readable if the variable isn't named clearly, as it obscures where exactly the method came from.

### Results Overview:
From the benchmark results, we see:
- **Local Variable**: 8,103,683.5 executions per second
- **Object Property**: 7,882,790.0 executions per second

This indicates that accessing the method via a local variable is significantly faster on the tested platform (Chrome Mobile on iOS). This can hint at optimizations done by JavaScript engines for local variable access.

### Other Considerations:
- The benchmark focuses on performance differences in a single scope. Factors influencing real-world performance might include additional context like memory usage, context switching, and garbage collection which are not taken into account in this benchmark alone.
- The results are specific to the JavaScript engine and the platform being used (in this case, Chrome on iOS). Different engines (e.g., V8, SpiderMonkey) may produce different performance characteristics.
- It's worth noting that while such micro-benchmarks provide insight into the performance characteristics of small code snippets, real-world applications often have more complex interactions and performance characteristics to consider.

### Alternatives:
- **Using Arrow Functions**: Instead of using traditional function expressions, arrow functions can be used. However, the performance implications of accessing arrow functions vs. object properties could vary.
- **Method Binding**: If the context of `this` is relevant, methods can be bound using `.bind()`, which allows you to set `this` explicitly. This approach would add overhead compared to local variable access.
- **Using Caching Mechanisms**: In more complex scenarios, caching as a technique for variable storage can greatly improve performance when dealing with methods or properties accessed frequently.

This benchmark showcases a common scenario in JavaScript and highlights a best practice that can lead to performance improvements in code. Using local variables for repeated access is a simple yet effective optimization technique across JavaScript applications.

Related benchmarks:

Object Property x Local Variable Accessing 1 (version: 1)

Comparing performance of: Object Property vs Local Variable

Created: one month ago by: Guest

Jump to the latest result

Object Property

Local Variable

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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