Benchmark: looptest - MeasureThat.net

Script Preparation code:

	for(var i= 0,arr = [];i<50000;i++) {
 arr.push({name:"name "+i,full_name:i+" full name "+ i,age:i});
}
  function fun(x) {
    return {name: x.name,fname:x.full_name};
  }

Tests:

map
newArr = arr.map(fun);
for
for (var i = 0,l = arr.length; i < l; i++) { newArr[i] = fun(arr[i]); }
forEach
arr.forEach(function(part, index, theArray) { newArr[index] = fun(arr[index]); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
for
forEach

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 break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark measures the performance of three different approaches to iterate over an array in JavaScript: `map`, `for` loop, and `forEach`. The benchmark is designed to test how quickly each approach can execute a function on each element of the array.

**Script Preparation Code**

The script preparation code creates an array with 50,000 elements, where each element has three properties: `name`, `full_name`, and `age`. This array will be used as input for the benchmarking tests.

**Html Preparation Code**

There is no HTML preparation code provided, which means that the benchmark doesn't test any HTML-related aspects of JavaScript.

**Individual Test Cases**

The benchmark consists of three individual test cases:

1. **`map`**: This test case uses the `map()` method to create a new array with the result of applying the `fun()` function to each element of the original array.
2. **`for`**: This test case uses a traditional `for` loop to iterate over the elements of the array, assigning the result of applying the `fun()` function to each element to a new array called `newArr`.
3. **`forEach`**: This test case uses the `forEach()` method to iterate over the elements of the array, calling the provided callback function (`fun`) on each element and assigning the result to the `newArr` array.

**Library Usage**

None of the benchmark tests use any external libraries or frameworks.

**Special JS Features/Syntax**

The benchmark doesn't use any special JavaScript features or syntax beyond what's required for the three approaches being tested. The `map()` and `forEach()` methods are part of the ECMAScript standard, while the traditional `for` loop is also a standard feature.

**Pros and Cons of Different Approaches**

Here's a brief overview of the pros and cons of each approach:

* **`map()`**:
	+ Pros: Efficient, concise, and easy to use.
	+ Cons: Can be slower than traditional loops for very large arrays due to the overhead of creating a new array.
* **Traditional `for` loop**:
	+ Pros: Control over iteration order and indexing, can be faster for very large arrays.
	+ Cons: More verbose, prone to off-by-one errors if not used carefully.
* **`forEach()`**:
	+ Pros: Concise, easy to use, and doesn't require manual indexing like traditional loops do.
	+ Cons: Can be slower than traditional loops due to the overhead of creating an array with callback functions.

**Other Alternatives**

There are other approaches that could be used in a benchmark like this, such as:

* **`reduce()`**: A method that applies a function to each element of an array and reduces it to a single value.
* **`filter()`**: A method that creates a new array with elements that pass a test provided by a callback function.
* **Closures**: A concept where a function has access to its own scope and the scope of its outer functions, which can be used in creative ways to optimize performance.

These alternatives might not be as directly relevant to this specific benchmark, but they demonstrate other aspects of JavaScript that could be tested in different contexts.

Related benchmarks:

looptest (version: 0)

Comparing performance of: map vs for vs forEach

Created: 9 years ago by: Guest

Jump to the latest result

map

for

forEach

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):