Benchmark: Compare comparison with null or undefined (nested3)

Script Preparation code:

var value = { a: 123 };
var valueNull = null;
var valueUndefined;

var zz;

function x() {
function y() {
function z() {
function f() {
function g() {
function h() {
function m() {
function n() {
function s() {
function t() {
function k() {
function q() {
function w() {
function o() {
function r() {
	zz = {
		callNull: function() {
			value === null;
			valueNull === null;
		},
		callUndefined: function() {
			value === undefined;
			valueUndefined === undefined;
		},
		callNotNull: function() {
			value !== null;
			valueNull !== null;
		},
		callNotUndefined: function() {
			value !== undefined;
			valueUndefined !== undefined;
		}
    };
} r();
} o();
} w();
} q();
} k();
} t();
} s();
} n();
} m();
} h();
} g();
} f();
} z();
} y();
} x();

function callNull() {
	zz.callNull();
}
function callUndefined() {
	zz.callUndefined();
}
function callNotNull() {
	zz.callNotNull();
}
function callNotUndefined() {
	zz.callNotUndefined();
}

Tests:

value === null
callNull();
value === undefined
callUndefined();
value !== null
callNotNull();
value !== undefined
callNotUndefined();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
value === null
value === undefined
value !== null
value !== undefined

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 28 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
value === null	78873656.0 Ops/sec
value === undefined	77033040.0 Ops/sec
value !== null	76912592.0 Ops/sec
value !== undefined	73936736.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 27 days ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON is focused on measuring the performance of JavaScript expressions that perform comparisons against `null` and `undefined`. It specifically evaluates four scenarios:

1. **Checking Equality with `null`**: 
   - **Benchmark Definition**: `callNull();`
   - This function checks if a variable `value` is strictly equal to `null` (`value === null`), and also whether a variable `valueNull` is strictly equal to `null`.

2. **Checking Equality with `undefined`**: 
   - **Benchmark Definition**: `callUndefined();`
   - This function checks if a variable `value` is strictly equal to `undefined` (`value === undefined`), and similarly checks if a variable `valueUndefined` is strictly equal to `undefined`.

3. **Checking Non-Equality with `null`**: 
   - **Benchmark Definition**: `callNotNull();`
   - This function checks if a variable `value` is not equal to `null` (`value !== null`), and also whether `valueNull` is not equal to `null`.

4. **Checking Non-Equality with `undefined`**: 
   - **Benchmark Definition**: `callNotUndefined();`
   - This function checks if a variable `value` is not equal to `undefined` (`value !== undefined`), and also checks if `valueUndefined` is not equal to `undefined`.

### Performance Results

The benchmark results indicate the number of executions per second for each of these comparisons. The results reveal:

- The equality check against `null` (`value === null`) is the fastest with approximately **78.87 million executions per second**.
- The equality check against `undefined` follows closely at about **77.03 million executions per second**.
- The non-equality check against `null` has about **76.91 million executions per second**.
- The non-equality check against `undefined` is the slowest at **73.94 million executions per second**.

### Pros and Cons of Approaches

- **Equality Checks (`===`)**: 
  - **Pros**: Direct and clear; using strict equality eliminates the risk of type coercion, leading to faster and more predictable results.
  - **Cons**: May be less performant than non-equality checks in certain contexts, though the difference here appears negligible.

- **Non-Equality Checks (`!==`)**:
  - **Pros**: Useful in contexts where it is needed to confirm the absence of a value, such as checks before executing logic or functions.
  - **Cons**: Can be marginally slower, as indicated by the benchmark results, and might introduce confusion about the intended checks if not carefully handled.

### Library and Code Explanation

The benchmark doesn't utilize any external libraries; it is entirely based on native JavaScript. The test revolves around primitive operations to assess performance in comparison to JavaScript's handling of `null` and `undefined`.

Both `null` and `undefined` represent "no value," but they are used in different contexts:
- `null` is typically an assignment value, meaning "no value intentionally."
- `undefined` represents a variable that has been declared but not assigned any value.

### Other Alternatives

- **Use of `typeof` operator**: Instead of direct comparisons, one can use `typeof variable === "undefined"` for checks against `undefined`. This approach is usually more descriptive but introduces overhead and is thus expected to be slower in performance benchmarks.

- **Logical Operators**: In practice, sometimes the logical OR operator (`||`) can be employed for default value assignments or checks, e.g., `let val = providedValue || default;`, but such expressions vary from direct comparisons and are not directly covered in this benchmark.

Overall, this benchmark offers insights into fundamental comparative operations in JavaScript, highlighting performance aspects that might guide developers in making decisions based on execution speed versus clarity of intent.

Related benchmarks:

Compare comparison with null or undefined (nested3) (version: 1)

Comparing performance of: value === null vs value === undefined vs value !== null vs value !== undefined

Created: 28 days ago by: Guest

Jump to the latest result

value === null

value === undefined

value !== null

value !== undefined

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 27 days ago):