Benchmark: Testing for false vs === undefined vs hasOwnProperty for undefined member 3

Script Preparation code:

var n ={};

Tests:

test truth
if(!n.foo) { }
test undefined
if(n.foo===undefined) { }
test hasOwnProperty
if(!Object.hasOwn(n,'foo')) { }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
test truth
test undefined
test hasOwnProperty

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The main goal of this benchmark is to compare the performance benefits of using different methods to check for the existence or absence of a property in an object.

The script preparation code creates an empty object `n` with no properties. The benchmark tests three scenarios:

1. `test truth`: Verifies that accessing an non-existent property (`n.foo`) returns false.
2. `test undefined`: Verifies that comparing `n.foo` to `undefined` returns true.
3. `test hasOwnProperty`: Verifies that using the `hasOwnProperty` method on the object checks for the existence of a specific property.

**Options Compared**

The benchmark compares two approaches:

1. **Using `!` operator**: Checks if a property exists by negating its value, e.g., `n.foo`.
2. **Using `=== undefined` comparison**: Directly compares the value to `undefined`, e.g., `n.foo === undefined`.

**Pros and Cons of Each Approach**

1. **Using `!` Operator**
	* Pros:
		+ Can be more concise.
		+ Less prone to errors due to strict type checking.
	* Cons:
		+ May be slower due to the use of the `!` operator.
		+ Does not provide explicit information about the property's existence.
2. **Using `=== undefined` Comparison**
	* Pros:
		+ Provides explicit information about the property's existence.
		+ Can be more readable, especially when dealing with complex logic.
	* Cons:
		+ May be slower due to the comparison operation.
		+ Can lead to errors if not used correctly.

**Other Considerations**

The benchmark assumes that modern JavaScript engines will optimize these comparisons in a similar way. However, there might be subtle differences between different browsers or engines.

Additionally, it's worth noting that using `hasOwnProperty` can be slower than other approaches due to the method call overhead. Nevertheless, it provides explicit information about the property's existence and is often considered more readable.

**Library Usage**

In this benchmark, no external libraries are used. However, some browsers (like Firefox) may use internal libraries or optimizations that are not explicitly mentioned in the benchmark definition.

**Special JS Features or Syntax**

None of the test cases explicitly use special JavaScript features like `let`, `const`, or arrow functions. The syntax is straightforward and focused on demonstrating the property existence checks.

In summary, this benchmark aims to compare the performance benefits of using different methods to check for property existence in an object, highlighting the pros and cons of each approach.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/109.0

Browser/OS: Firefox 109 on Ubuntu

View result in a separate tab

Test name	Executions per second
test truth	1771618304.0 Ops/sec
test undefined	1736551424.0 Ops/sec
test hasOwnProperty	1569789824.0 Ops/sec

Related benchmarks:

Testing for false vs === undefined vs hasOwnProperty for undefined member 3 (version: 0)

Is there a performance benefit to replacing === undefined with a logical test?

Comparing performance of: test truth vs test undefined vs test hasOwnProperty

Created: one year ago by: Guest

Jump to the latest result

test truth

test undefined

test hasOwnProperty

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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