Benchmark: void 0 and undefined in deep call stack - 5

Tests:

a == undefined
function compare(n= 1e3){ let a = undefined; for(let i = 0; i < n; i++){ a === undefined; } } function deep(num){ if (num === 0) { compare(); return; } else { deep(num-1); } } deep(1);
a == void 0
function compare(n= 1e3){ let a = undefined; for(let i = 0; i < n; i++){ a === void 0; } } function deep(num){ if (num === 0) { compare(); return; } else { deep(num-1); } } deep(1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
a == undefined
a == void 0

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
a == undefined	18882.2 Ops/sec
a == void 0	1876524.9 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark definition provides two script files that are used to create test cases:

1. `compare.js`: This script defines a function `compare` that checks if `a` is equal to `undefined`. The function loops `n` times, where `n` is set to 10^3 (1000) by default.
2. `deep.js`: This script defines a recursive function `deep` that calls itself with decreasing values of `num` until it reaches 0. When `num` is 0, the `compare` function is called.

**Test Cases**

There are two test cases defined in the JSON:

1. "a == undefined"
	* This test case uses the `compare.js` script and checks if the `compare` function takes longer to execute when comparing `undefined` instead of `void 0`.
2. "a == void 0"
	* This test case uses the `deep.js` script, which creates a deep call stack by recursively calling itself with decreasing values of `num`. The comparison is done using `===` operator.

**Options Compared**

The two test cases compare the performance of comparing `undefined` and `void 0` in different contexts:

* In the first test case (`"a == undefined"`), the focus is on the scope chain when calling `compare` from a deep stack.
* In the second test case (`"a == void 0"`), the focus is on the performance of recursive function calls and comparisons using `===` operator.

**Pros and Cons**

Here are some pros and cons of each approach:

1. "a == undefined"
	* Pros: This test case focuses on a specific scenario where scope chain matters, making it easier to identify performance issues related to this aspect.
	* Cons: The test case might not accurately represent real-world usage, as `undefined` is often used in conditional statements rather than comparisons.
2. "a == void 0"
	* Pros: This test case covers a more general scenario that reflects common use cases for comparing values using `===`.
	* Cons: The recursive function calls and comparisons might not accurately represent real-world performance issues.

**Libraries and Special JS Features**

None of the provided script files use any external libraries. However, some JavaScript features like arrow functions (`=>`) are used in the code.

**Other Considerations**

When running these benchmarks, it's essential to consider the following:

* Browser rendering: Some browsers might have different performance characteristics due to rendering engines and memory management.
* Hardware-specific optimizations: Different hardware configurations (e.g., Intel vs. ARM-based devices) can impact performance due to varying instruction sets and caching mechanisms.

**Alternatives**

If you wanted to create alternative benchmark test cases, consider the following:

1. Use `Object.prototype.hasOwnProperty.call` instead of `===` for comparison.
2. Compare the performance of comparing values using `===` vs. `==`.
3. Test the impact of scope chain on performance in different contexts (e.g., function calls, loops).
4. Create a benchmark that measures the performance of recursive functions with varying levels of recursion.

By exploring alternative test cases and considerations, you can gain a deeper understanding of the performance implications of JavaScript code and optimize your applications accordingly.

Related benchmarks:

void 0 and undefined in deep call stack - 5 (version: 0)

Check performance degradation due to scope chain when undefined is called from deep stack

Comparing performance of: a == undefined vs a == void 0

Created: 2 years ago by: Guest

Jump to the latest result

a == undefined

a == void 0

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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