Benchmark: Symbol vs String property square bracket a

Script Preparation code:

var foo = {};
var sym = Symbol("key");
var str = "ke";

Tests:

Symbol
foo[sym] = 1;
String
foo[str + "y"] = 1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Symbol
String

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested.

**What is being tested?**

The test case measures the performance difference between using a `Symbol` property versus a string literal (`"ke"`) when accessing an object's property. Specifically, it tests how fast each approach is to set a value of 1 on an object `foo`.

**Options compared:**

Two options are being compared:

1. **Symbol**: Using a `Symbol` as a property name, created using the `Symbol()` function.
2. **String**: Using a string literal (`"ke"`) as a property name.

**Pros and Cons of each approach:**

* **Symbol**: Advantages:
	+ Unique and unique-to-run-time generated values, reducing collisions with other variables.
	+ Less likely to be accidentally overwriting existing properties due to variable naming conventions.
	+ Can improve performance by avoiding string interpolation.
* Disadvantages:
	+ Additional overhead for creating a symbol at runtime.
	+ May not provide significant benefits in all cases (e.g., when the property name is short and unlikely to collide).
* **String**: Advantages:
	+ Well-established and widely supported syntax.
	+ Easy to understand and read.
	+ Often faster than symbols due to reduced overhead for creating a string literal at runtime.
* Disadvantages:
	+ More prone to collisions with other variables that have the same name.
	+ May lead to overwriting existing properties if not careful with naming conventions.

**Library usage:**

The `Symbol` property is being used, which is a built-in JavaScript language feature introduced in ECMAScript 2015. The purpose of using `Symbol` is to create unique and non-overlapping property names.

**Special JS feature or syntax:**

This test case uses the `Symbol()` function to create a symbol at runtime, which is a special syntax for creating unique symbols. This allows for more efficient and collision-free property access.

**Benchmark preparation code:**

The script preparation code creates an object `foo` and defines two variables: `sym` (a symbol) and `str` (the string literal `"ke"`). The final line of the code sets a value of 1 on each object using the corresponding variable name.

**Other alternatives:**

If you wanted to test alternative approaches, you could consider:

* Using an array index instead of a property name.
* Using a function or method to access the object's properties.
* Testing different data types for the property names (e.g., numbers, booleans).
* Evaluating the performance impact of using `in` operator vs. bracket notation (`[]`) for accessing object properties.

Note that these alternatives would require modifying the benchmark code and may not provide comparable results due to differences in syntax and semantics.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36

Browser/OS: Chrome 113 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Symbol	8152597.5 Ops/sec
String	5555626.5 Ops/sec

Related benchmarks:

Symbol vs String property square bracket a (version: 0)

Comparing performance of: Symbol vs String

Created: one year ago by: Guest

Jump to the latest result

Symbol

String

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):