Benchmark: for loop vs every

Script Preparation code:

nums = [1,2,3,4,5,6,7,8,9,10,3,51,124,23,235,-124,25,253,256,315]
cond = x => x >= 0;

Tests:

for loop
let result = true; for (let i = 0; i < nums.length; i++) { if (!(nums[i] >= 0)) { result = false; break; } }
every
nums.every(cond);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for loop
every

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36

Browser/OS: Chrome 142 on Linux

View result in a separate tab

Test name	Executions per second
for loop	17397888.0 Ops/sec
every	57015796.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmarking test and explain what's being tested.

**What is being tested?**

MeasureThat.net is testing two approaches to iterate over an array in JavaScript: traditional `for` loop and the `every()` method.

The `for` loop uses a manual index (`i`) to access each element in the array, while the `every()` method takes a callback function (in this case, a simple lambda expression) that checks if all elements satisfy a condition. The `every()` method is designed to take advantage of JavaScript's optimization capabilities by reusing the same lambda function for all iterations.

**Options compared**

There are two main options being compared:

1. **For loop**: This traditional approach uses a manual index (`i`) to access each element in the array.
2. **Every() method**: This optimized approach uses a callback function (lambda expression) that checks if all elements satisfy a condition, allowing JavaScript to reuse this function for all iterations.

**Pros and cons of each approach:**

* **For loop**:
	+ Pros:
		- Simple and well-known
		- Can be easily optimized by inlining the condition
	+ Cons:
		- Requires manual index management
		- May not take advantage of JavaScript's optimization capabilities
* **Every() method**:
	+ Pros:
		- Optimized for performance, reusing the same lambda function for all iterations
		- Simple and concise syntax
	+ Cons:
		- May have higher overhead due to the additional function call

**Library usage**

There is no explicit library used in this benchmark. However, it's worth noting that the `every()` method relies on JavaScript's built-in functionality.

**Special JS feature or syntax**

The `every()` method uses a special JavaScript syntax for callback functions (lambda expressions), which allows for concise and expressive code. This syntax is designed to be easy to read and understand.

**Benchmark preparation code**

The provided script preparation code sets up an array (`nums`) with 15 elements, including one out-of-range value (51). The lambda expression (`cond`) checks if each element is greater than or equal to 0. The `for` loop iterates over the array using a manual index, while the `every()` method uses its optimized approach.

**Alternative approaches**

Other alternatives for iterating over an array in JavaScript include:

* **Map() and callback**: While not directly applicable here, using `map()` with a callback function can be a viable alternative. However, it would require additional processing to filter out elements that don't meet the condition.
* **Reduce() and accumulator**: Similar to `map()`, `reduce()` could be used, but again, it would require additional processing.
* **Custom implementation using index management**: An alternative approach would be to use a custom implementation that manages indices manually, similar to the traditional `for` loop. However, this would likely result in less optimized performance.

Keep in mind that these alternatives might have different use cases or requirements, and the `every()` method is specifically designed for this type of iteration.

Related benchmarks:

for loop vs every (version: 0)

iterating over an array to test whether every element satisfies a condition the for loop uses "inlining" (the condition is right there, without an extra function call) the call to every uses the predefined lambda ("cond")

Comparing performance of: for loop vs every

Created: 5 years ago by: Guest

Jump to the latest result

for loop

every

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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