Benchmark: Object.values overhead cost

Script Preparation code:

var myObj = {};
for (var i = 0; i < 1000; i++) {
    myObj['val' + i] = 'val' + i;
}
var myObjValues = Object.values(myObj);

Tests:

Call Object.values on each execution
var curObjValues = Object.values(myObj); var myStr = ''; for (var i = 0; i < curObjValues.length; i++) { myStr += curObjValues[i]; }
Use shared Object.values
var curObjValues = myObjValues; var myStr = ''; for (var i = 0; i < curObjValues.length; i++) { myStr += curObjValues[i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Call Object.values on each execution
Use shared Object.values

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser/OS: Chrome 141 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Call Object.values on each execution	17097.1 Ops/sec
Use shared Object.values	334501.8 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 benchmarking test cases and explain what is being tested, compared, and their pros and cons.

**Overview**

The test measures the overhead cost of two approaches to using `Object.values()` in JavaScript:

1. **Call Object.values on each execution**: This approach creates a new variable `curObjValues` and assigns it the result of calling `Object.values()` on `myObj` for each execution.
2. **Use shared Object.values**: This approach reuses the same variable `myObjValues` created in the benchmark preparation code and uses it for all executions.

**What is being tested**

The test measures the overhead cost (in terms of number of executions per second) of these two approaches on a specific JavaScript function that concatenates the values returned by `Object.values()` into a string.

**Options compared**

Two options are compared:

1. **Call Object.values on each execution**: This approach involves creating a new variable and calling `Object.values()` for each execution, which means reassigning the result to a new variable every time.
2. **Use shared Object.values**: This approach reuses the same variable and calls `Object.values()` only once in the preparation code.

**Pros and Cons**

**Call Object.values on each execution:**

Pros:

* Each execution gets its own copy of the object values, which might be useful if multiple threads or processes are using this function concurrently.
* The overhead is more predictable since it's happening for each execution.

Cons:

* Creates a new variable every time, which can lead to memory allocation and deallocation overhead.
* The result of `Object.values()` is lost after the first assignment, so reusing values across executions would require additional storage.

**Use shared Object.values:**

Pros:

* Reuses the same variable, reducing memory allocation and deallocation overhead.
* Can reuse values across executions without needing additional storage.

Cons:

* The value of `myObjValues` is not reset after each execution, which means it will be affected by previous assignments (e.g., if another test case uses this shared variable).
* The overhead might be higher due to the need for synchronization or locking when accessing and modifying a shared resource.

**Library and Purpose**

The `Object.values()` method is a built-in JavaScript method that returns an array of values for each own enumerable property in an object. In this benchmark, it's used to extract values from the `myObj` object created in the preparation code.

**Special JS feature or syntax**

None mentioned in this test case.

**Other alternatives**

If you want to explore other approaches, here are some additional options:

* Use a caching mechanism (e.g., a WeakMap) to store and reuse results of expensive function calls.
* Consider using a just-in-time (JIT) compiler or a ahead-of-time (AOT) compiler for JavaScript to optimize the performance of `Object.values()`.
* Look into alternative data structures, such as arrays or sets, that might offer better performance characteristics for this specific use case.

Keep in mind that these alternatives might require significant changes to your benchmarking setup and test code.

Related benchmarks:

Object.values overhead cost (version: 2)

Comparing performance of: Call Object.values on each execution vs Use shared Object.values

Created: 7 years ago by: Registered User

Jump to the latest result

Call Object.values on each execution

Use shared Object.values

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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