Benchmark: mutate-vs-map - MeasureThat.net

Script Preparation code:

var arr = [];
for (var i = 0; i < 1000; i++) {
    arr[i] = {
        name: `${i}`,
        value: i
    };
}

function someFn(i) {
    const x24 = i.value * 3 * 8;
    i.value = x24;
    i.name = `${x24}`;
    return i;
}

Tests:

for of
for (var y of arr) { someFn(y); }
map
arr.map(item => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for of
map

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its results.

**Benchmark Overview**

The `mutate-vs-map` benchmark compares two approaches to modify an array: using a `for...of` loop and using the `map()` method.

**Script Preparation Code**

The script preparation code creates an empty array `arr` with 1000 elements, each containing `name` and `value` properties. The `someFn` function is defined to take an object `i` as an argument, modify its `value` property by multiplying it by 3 and 8, update the `name` property with the result, and return the modified object.

**Html Preparation Code**

There is no HTML preparation code provided, which suggests that this benchmark only runs in a headless browser or doesn't require any specific HTML setup.

**Individual Test Cases**

The two test cases are:

1. `for of`: This test case uses a `for...of` loop to iterate over the array and calls the `someFn` function on each element.
2. `map`: This test case uses the `map()` method to create a new array with the modified elements.

**Benchmark Results**

The latest benchmark results show two browsers (Firefox 119) running on different platforms:

1. `for of`: 34940.9375 executions per second
2. `map`: 34092.4296875 executions per second

**Options Compared**

The two options being compared are:

* Using a `for...of` loop to iterate over the array and call a function on each element.
* Using the `map()` method to create a new array with modified elements.

**Pros and Cons of Each Approach**

1. **For...of Loop**:
	* Pros:
		+ Can be more efficient for small arrays or when working with older browsers that don't support `map()`.
		+ Allows for easier handling of asynchronous operations.
	* Cons:
		+ Can be slower for large arrays due to the overhead of creating and managing the loop iterator.
		+ May not be suitable for scenarios where the function needs to be called on each element multiple times.
2. **Map**:
	* Pros:
		+ Generally faster for large arrays due to its use of SIMD instructions and caching.
		+ Returns a new array, which can be useful when working with immutable data structures or when preserving original array state is required.
	* Cons:
		+ Can be less efficient in older browsers that don't support `map()`.
		+ May require additional memory allocation for the new array.

**Library**

The `map()` method uses the Array.prototype.map() method, which is a built-in JavaScript method. The purpose of this method is to create a new array with the results of applying a provided function on every element in an existing array.

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax used in this benchmark that would affect its execution or behavior.

**Alternatives**

Some alternative approaches to modifying arrays include:

* Using `forEach()`: While not as efficient as `map()` for large arrays, `forEach()` can be a suitable option when working with small arrays or older browsers.
* Using `reduce()`: This method can be used to create a new array by reducing the original array to a single value. However, it may not be as efficient as `map()` and requires more complex logic to achieve the desired result.

Keep in mind that the best approach depends on the specific requirements of your use case, such as performance, memory usage, or data structure preservation.

Related benchmarks:

mutate-vs-map (version: 0)

Comparing performance of: for of vs map

Created: 3 years ago by: Guest

Jump to the latest result

for of

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):