Benchmark: Property Assignment vs Symbol Assignment

Script Preparation code:

window.sym = Symbol("key");
window.obj = {a: 1, b: 2};

Tests:

Property
obj.key = "value";
Symbol
obj[sym] = "value";

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Property
Symbol

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark and explain what's being tested, the options being compared, their pros and cons, and other considerations.

**Benchmark Overview**

The benchmark is designed to compare the performance of property assignment versus symbol assignment in JavaScript. The test cases measure how quickly a simple assignment operation can be executed using either property assignment (e.g., `obj.key = "value"`) or symbol assignment (e.g., `obj[sym] = "value"`).

**Test Cases**

There are two test cases:

1. **Property Assignment**: This test case measures the performance of assigning a value to a property using the dot notation (`obj.key = "value"`).
2. **Symbol Assignment**: This test case measures the performance of assigning a value to a symbol using bracket notation (`obj[sym] = "value"`).

**Options Being Compared**

The two options being compared are:

1. **Property Assignment (Dot Notation)**: `obj.key = "value"`
2. **Symbol Assignment (Bracket Notation)**: `obj[sym] = "value"`

**Pros and Cons of Each Approach**

* **Property Assignment (Dot Notation)**:
	+ Pros:
		- Widely supported and well-known syntax.
		- Easy to read and write.
	+ Cons:
		- May incur additional overhead due to string interpolation or property name resolution.
* **Symbol Assignment (Bracket Notation)**:
	+ Pros:
		- Can be faster than dot notation, especially when dealing with large numbers of properties.
		- Reduces collisions between property names.
	+ Cons:
		- Less widely supported and less familiar syntax for some developers.

**Library and Its Purpose**

In this benchmark, the `Symbol` library is used to create symbols. Symbols are a primitive data type in JavaScript that can be used as property keys or values. They were introduced in ECMAScript 2015 (ES6) as a way to create unique and immutable identifiers.

**Special JS Feature or Syntax**

This benchmark does not use any special JavaScript features or syntax, such as async/await, promises, or arrow functions.

**Other Considerations**

When working with property assignment and symbol assignment, it's essential to consider the following:

* **Property Name Resolution**: When using dot notation, the browser may need to resolve the property name by traversing the object prototype chain. This can incur additional overhead.
* **String Interpolation**: When using dot notation, string interpolation may occur when assigning a value to a property that is a string literal.

**Alternatives**

If you're looking for alternative ways to measure performance in JavaScript, consider the following:

1. **Benchmarking libraries**: Tools like Benchmark.js, Fastify's benchmarking module, or Microbenchmark can help you write and run benchmarks.
2. **Performance profiling tools**: Instruments like Chrome DevTools' Performance Profiler or Firefox Developer Edition's Performance Tab can help you identify performance bottlenecks in your code.
3. **JavaScript engines**: Compare the performance of different JavaScript engines, such as V8 (used by Google Chrome), SpiderMonkey (used by Mozilla Firefox), or V8's sibling engine, Squirrelfish.

By understanding these alternatives and considerations, you can develop a more comprehensive approach to benchmarking and optimizing your JavaScript code.

Related benchmarks:

Property Assignment vs Symbol Assignment (version: 0)

Comparing performance of: Property vs Symbol

Created: 5 years ago by: Guest

Jump to the latest result

Property

Symbol

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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