Benchmark: compare for loop with filter

Script Preparation code:

var objectSize = 1000000;
var iterations = 20;

var anyStringObject = {};

var start = 0;
var end = 0;

for (var i = 0; i < objectSize; i++) {
  anyStringObject[`key${i}`] = `val${i}`;
}

var condition = (key) => true;

Tests:

for loop
for (var i = 0; i < iterations; i++) { var objectKeys = []; var keys = Object.keys(anyStringObject); var length = keys.length; for (var index = 0; index < length; index++) { if (condition(keys[index])) { objectKeys.push(keys[index]); } } }
filter
for (var i = 0; i < iterations; i++) { var keys = Object.keys(anyStringObject); keys.filter((key) => condition(key)); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
filter

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

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This benchmark compares two methods for filtering keys from a large object in JavaScript: a traditional `for` loop and the `.filter()` array method.

**For Loop Approach:**

* **Description:** This approach iterates through each key in the object using `Object.keys()` and checks if it satisfies a given condition. If true, the key is added to a new array (`objectKeys`).
* **Pros:**  Can be more understandable for beginners as it directly mimics the manual iteration process.
* **Cons:** Can be less concise than using built-in methods, and might perform slightly worse in some cases due to manual loop management.

**`.filter()` Method Approach:**

* **Description:** This approach leverages the built-in `.filter()` method on an array of keys obtained from `Object.keys(anyStringObject)`. The function provided to `.filter()` checks each key against the given condition.  Only keys that pass the condition are included in the resulting filtered array.
* **Pros:** More concise and expressive, potentially more efficient due to optimized implementation in JavaScript engines. 
* **Cons:** Can be less intuitive for beginners who aren't familiar with higher-order array methods.

**Considerations:**

* **Object Size:** For very large objects, the performance difference between these approaches might become more noticeable.  
* **Condition Complexity:** The complexity of the condition function can also impact performance.

**Alternatives:**

* **Other Higher-Order Array Methods:**  You could explore using methods like `.forEach()` or `.some()`, depending on your specific needs beyond just filtering. 
* **Libraries:** Some libraries (like Lodash) provide optimized versions of common array operations, including filtering. This might be beneficial if you work with large datasets frequently.

**Remember:** Benchmark results can vary based on the environment (browser, hardware), JavaScript engine version, and other factors. It's always best to run your own benchmarks with representative data to get accurate performance measurements for your specific use case.

Related benchmarks:

compare for loop with filter (version: 0)

Comparing performance of: for loop vs filter

Created: 4 years ago by: Guest

Jump to the latest result

for loop

filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):