Benchmark: type coercion null

Script Preparation code:

var value = null;

Tests:

not (!)
!value
truthy (== undefined)
value == null
truthy with different type (== null)
value == undefined
strict equality (=== undefined)
value === null

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
not (!)
truthy (== undefined)
truthy with different type (== null)
strict equality (=== undefined)

Fastest: N/A

Slowest: N/A

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/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
not (!)	35317556.0 Ops/sec
truthy (== undefined)	35370536.0 Ops/sec
truthy with different type (== null)	12264591.0 Ops/sec
strict equality (=== undefined)	35376224.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark definition represents a simple JavaScript expression that is being measured. In this case:

* `var value = null;` sets up a variable `value` to be `null`.
* The script preparation code is empty, which means no additional setup or initialization is needed.
* The HTML preparation code is also empty, indicating that the benchmark does not require any specific HTML context.

**Individual Test Cases**

There are four test cases:

1. `"!value"`: This test case checks if `!` (not) negates a value of type "undefined". In JavaScript, using `!` with an undefined value returns `true`.
2. `"value == null"`: This test case checks for strict equality (`==`) between the variable `value` and `null`. Since `value` is initialized as `null`, this should return `true`.
3. `"value == undefined"`: Similar to the previous test, but uses strict equality (`==`) instead of loose equality (`==`). In JavaScript, using `==` with an undefined value returns `undefined`, not `false`.
4. `"value === null"`: This test case checks for strict equality (`===`) between the variable `value` and `null`. Since `value` is initialized as `null`, this should return `true`.

**Library Used**

None of the provided test cases use a specific JavaScript library.

**Special JS Feature or Syntax**

The only special feature used in these test cases is the "not" operator (`!`) in the first test case. The `!` operator negates its operand, returning `true` if the operand is falsy (including `undefined`). This is a relatively simple and common JavaScript feature.

**Pros and Cons of Different Approaches**

1. **Loose Equality (`==`)**:
	* Pros: Easy to read and write.
	* Cons: Can lead to unexpected behavior due to type coercion, e.g., comparing numbers with strings using `==`.
2. **Strict Equality (`===`)**:
	* Pros: Ensures that both operands are of the same value and type.
	* Cons: May be more verbose, as it requires specifying both value and type equality.

**Other Considerations**

The benchmark measures the performance difference between these four test cases on different browsers and devices. This can help identify potential issues with JavaScript engine optimizations or library implementations.

**Alternative Approaches**

If you wanted to modify the benchmark to include alternative approaches, you could consider:

1. Using a more complex expression that involves multiple operators or data types.
2. Adding additional variables or setup code to make the benchmark more challenging.
3. Changing the comparison operator from `==` to `===`.
4. Introducing timing-related functions (e.g., `setTimeout()`) to measure execution time.

Keep in mind that modifying these test cases might alter their meaning and intent, so it's essential to ensure that any changes align with your testing goals.

Related benchmarks:

type coercion null (version: 0)

Comparing performance of: not (!) vs truthy (== undefined) vs truthy with different type (== null) vs strict equality (=== undefined)

Created: one year ago by: Guest

Jump to the latest result

not (!)

truthy (== undefined)

truthy with different type (== null)

strict equality (=== undefined)

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):