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Memory Usage
(version: 0)
Benchmark.js
Comparing performance of:
undefined vs delete
Created:
6 years ago
by:
Guest
Go to the latest result
Script Preparation code:
window.x = { a: 1 };
Tests:
undefined
x.a = undefined;
delete
delete x.a;
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
undefined
delete
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36
Browser/OS:
Chrome 136 on Windows
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=605882" width="100%" height="500px"></iframe>
undefined
131.9M/s
delete
81.6M/s
View exact numbers
Test name
Executions per second
✓
undefined
131,898,568 Ops/sec
delete
81,634,360 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'd be happy to explain what's being tested in the provided JSON benchmark data. **Overview** The benchmark measures the memory usage of JavaScript variables when assigned new values. It specifically tests the behavior of `undefined`, `delete` statements, and variable assignments with no initial value. **Benchmark Definition** The benchmark definition is a simple assignment statement that creates an object `x` with a property `a`. The `Script Preparation Code` section provides an initial state by setting `window.x = { a: 1 };`. This means the test starts with a variable `x` having a value of `{ a: 1 }`. **Options Compared** There are two options being compared: 1. **Undefined**: The first test case assigns `undefined` to `x.a`. This tests how JavaScript handles the assignment of `undefined` to a property. 2. **Delete**: The second test case uses the `delete` operator to delete the property `a` from the object `x`. **Pros and Cons** * **Undefined:** * Pros: * Simplifies understanding of variable assignments in JavaScript * Easy to implement and understand * Cons: * May not accurately reflect real-world scenarios where variables are initialized with a specific value or type * Can be misleading if the test is run on systems where garbage collection happens immediately after assignment, potentially hiding the impact of the `undefined` assignment. * **Delete:** * Pros: * More representative of common JavaScript usage patterns (e.g., clearing data from an object or array) * Can help identify performance issues related to memory management and variable deallocation * Cons: * May require additional setup or handling to ensure the test is run in a state where `delete` has no unintended side effects **Other Considerations** * The benchmark doesn't account for caching, which might influence the results. In some browsers, assigning an object with a specific property can cause it to be cached and reused instead of being created anew. * The `window.x = {a: 1};` setup is used to initialize `x.a`. This means that if you were running this test multiple times consecutively without resetting the variable, `x.a` would retain its value from previous runs. This could lead to inconsistent results and might not accurately represent real-world usage patterns. **Library Usage** The benchmark doesn't explicitly use any libraries. However, it relies on the browser's JavaScript engine and its built-in features like `delete`. The test is designed to work with a basic understanding of JavaScript syntax and semantics. **Special JS Features or Syntax** There are no special features or syntaxes being tested in this benchmark. The code is straightforward and only uses standard JavaScript assignment operators and the `delete` operator. **Alternatives** If you were interested in exploring different approaches, some alternatives could include: * Creating multiple test cases to explore various scenarios (e.g., assigning objects with specific properties or values) * Using a more complex object structure to evaluate memory usage during variable assignments * Integrating this benchmark into a larger suite of tests that assess the performance and behavior of different JavaScript engines under various conditions
Comments
Confirm delete:
Do you really want to delete benchmark?