Benchmark: Iterate object - MeasureThat.net

HTML Preparation code:

<html>
  <head></head>
  <body>
    <script type="text/javascript">
    	var doc = new Document({width: 50, height: 50});
    </script>
  </body>
</html>

Script Preparation code:

    var Document = function(Config) {
      this.config = {
        worker: true,
        width: "auto",
        height: "auto"
      };
      this.init(Config);
    };

Tests:

prop not declared
Document.prototype.init = function(Config) { var config = this.config; if(typeof Config == "object") { for(prop in Config) { if(config.hasOwnProperty(prop)) this.config[prop] = Config[prop]; } } };
prop declared
Document.prototype.init = function(Config) { var config = this.config; if(typeof Config == "object") { for(var prop in Config) { if(config.hasOwnProperty(prop)) this.config[prop] = Config[prop]; } } };
prop not declared without ref
Document.prototype.init = function(Config) { if(typeof Config == "object") { for(prop in Config) { if(this.config.hasOwnProperty(prop)) this.config[prop] = Config[prop]; } } };
prop declared without ref
Document.prototype.init = function(Config) { if(typeof Config == "object") { for(var prop in Config) { if(this.config.hasOwnProperty(prop)) this.config[prop] = Config[prop]; } } };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
prop not declared
prop declared
prop not declared without ref
prop declared without ref

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

**Overview**

The provided JSON represents a JavaScript microbenchmark test case for measuring the performance of different approaches to iterate over object properties in JavaScript. The test case is designed to compare the execution time of four different scenarios: using `for...in` loop with and without reference (`this`) variables, and `for...of` loop.

**Benchmark Definition**

The benchmark definition specifies the behavior of the `Document.prototype.init` method, which is called on an instance of the `Document` class. The method takes a `Config` object as an argument and iterates over its properties to update the `config` object of the `Document` instance.

There are four different benchmark definitions:

1. "prop not declared" - This scenario tests the iteration over the `config` object's properties without checking for reference variables (`this`).
2. "prop declared" - This scenario tests the iteration over the `Config` object's properties and updates the `config` object with the new values.
3. "prop not declared without ref" - This scenario is similar to the first one, but it uses a `for...in` loop without referencing the `this` variable.
4. "prop declared without ref" - This scenario tests the iteration over the `Config` object's properties and updates the `config` object with the new values, but does not use a reference variable (`this`).

**Options Compared**

The test case compares the performance of four different approaches:

1. Using `for...in` loop with reference variable (`this`)
2. Using `for...in` loop without reference variable (`this`)
3. Using `for...of` loop
4. Not iterating over properties at all (i.e., using `Object.assign` or similar)

**Pros and Cons**

1. **Using `for...in` loop with reference variable (`this`)**:
	* Pros: Efficient iteration over object properties, no overhead of creating a new iterator.
	* Cons: May not work correctly if the `config` object has inherited properties.
2. **Using `for...in` loop without reference variable (`this`)**:
	* Pros: Similar to the previous approach, but may be slightly faster since it doesn't create a reference variable.
	* Cons: Still has the overhead of creating a new iterator and may not work correctly with inherited properties.
3. **Using `for...of` loop**:
	* Pros: More modern and efficient iteration approach, less prone to errors.
	* Cons: May not be supported in older browsers or versions of JavaScript.
4. **Not iterating over properties at all**:
	* Pros: Fastest approach since it avoids any overhead of iteration.
	* Cons: Not practical for updating object properties.

**Other Considerations**

* The test case uses a `Document` class to create an instance and call the `init` method on it. This is likely done to simulate a real-world scenario where an object needs to be initialized with some configuration data.
* The test results are reported in terms of executions per second, which provides a good measure of performance.
* The benchmark is executed multiple times for each test case, and the average execution time is calculated.

**Alternatives**

Other alternatives to this approach include:

1. Using `Object.assign` or similar methods to update object properties.
2. Using a library like Lodash that provides utility functions for working with objects.
3. Using a different iteration approach, such as using `forEach` loop or recursion.
4. Measuring the performance of other JavaScript features, such as closures or async/await.

Note that the choice of alternative approaches depends on the specific requirements and use cases of the project.

Latest run results:

Run details: (Test run date: 8 years ago)

User agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0

Browser/OS: Firefox 48 on Windows 8.1

View result in a separate tab

Test name	Executions per second
prop not declared	38738664.0 Ops/sec
prop declared	31487398.0 Ops/sec
prop not declared without ref	30435558.0 Ops/sec
prop declared without ref	27244124.0 Ops/sec

Related benchmarks:

Iterate object (version: 0)

Comparing performance of: prop not declared vs prop declared vs prop not declared without ref vs prop declared without ref

Created: 8 years ago by: Guest

Jump to the latest result

prop not declared

prop declared

prop not declared without ref

prop declared without ref

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):