Benchmark: Array loop vs foreach vs map - larger

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 50000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

Tests:

foreach
arr.forEach(function (item){ someFn(item); })
for
for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]); }
map
arr.map(item => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
map

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that tests three different approaches for iterating over an array and performing a calculation on each element:

1. `Array.prototype.forEach()`: A method that iterates over the elements of an array, executing a provided callback function for each element.
2. `for...of` loop (not explicitly used in this case, but implied): A type of loop that iterates over the elements of an array using a `for...of` statement.
3. `Array.prototype.map()`: A method that creates a new array with the results of applying a provided function to each element of the original array.

**Options comparison**

The three options being compared are:

* `forEach`: Iterating over the array and executing a callback function for each element.
	+ Pros: Easy to use, concise syntax. Well-suited for cases where you need to perform some action on each element without modifying the array.
	+ Cons: Can be less efficient than other methods due to the overhead of the callback function invocation, especially when dealing with large arrays.
* `for`: A traditional loop that iterates over the elements of an array using a counter variable.
	+ Pros: Generally faster and more efficient than `forEach` or `map`, as it avoids the overhead of the callback function invocation. Also allows for direct access to the element being processed.
	+ Cons: Can be more verbose and less readable than `forEach` or `map`, especially when dealing with complex loops.
* `map`: Creating a new array with the results of applying a provided function to each element of the original array.
	+ Pros: Creates a new array, which can be beneficial for certain use cases (e.g., when you need to preserve the original array and create a new one with modified data). Can also be more efficient than `forEach` in some cases due to the avoidance of callback function invocation overhead.
	+ Cons: Returns a new array, which may not be desirable if you only want to perform an action on each element without modifying the original array. Also can be less readable and more verbose than `for`.

**Library considerations**

None.

**Special JS feature/syntax consideration**

No special features or syntax are used in this benchmark that would require additional explanation.

**Alternative approaches**

Other alternative approaches for iterating over arrays and performing calculations include:

* `Array.prototype.reduce()`: A method that applies a reduction function to each element of the array, reducing it to a single value.
* Using `setInterval()` with an array of values: This approach involves using the `setInterval()` function to execute a callback function repeatedly for a specified number of iterations, which can be useful in certain cases where you need to perform multiple actions on each element.

However, these alternative approaches are not being tested in this benchmark.

It's worth noting that measuring the performance of small benchmarks like this one is not always indicative of real-world performance differences. Larger, more complex scenarios may reveal different results due to various factors such as caching, optimization techniques, and hardware variability.

Related benchmarks:

Array loop vs foreach vs map - larger (version: 0)

Comparing performance of: foreach vs for vs map

Created: 5 years ago by: Guest

Jump to the latest result

foreach

for

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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