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Map vs For Loop
(version: 1)
Benchmark.js
Comparing performance of:
Map vs For Loop
Created:
9 years ago
by:
Registered User
Go to the latest result
Script Preparation code:
var a = []; for (var i = 0; i < 1e6; i++) { a[i] = Math.random(); }
Tests:
Map
var b = a.map(n => n * 2); return b;
For Loop
var b = []; for (var i = 0; i < a.length; i++) { b[i] = a[i] * 2; } return b;
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
Map
For Loop
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Safari/605.1.15
Browser/OS:
Safari 17 on Mac OS X 10.15.7
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=505139" width="100%" height="500px"></iframe>
Map
374/s
For Loop
13/s
View exact numbers
Test name
Executions per second
✓
Map
374 Ops/sec
For Loop
13 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
**What is being tested?** The provided JSON represents a benchmark test case that compares the performance of two approaches to double each element in an array: using the `map()` function versus a traditional `for` loop. **Options compared:** 1. **Map()**: The `map()` function is a built-in JavaScript method that creates a new array with the results of applying a provided function on every element in this array. 2. **For Loop**: A traditional `for` loop is used to iterate over each element in the array and manually double its value. **Pros and Cons:** * **Map()**: * Pros: * More concise and readable code * Easier to maintain and extend * Handles errors and edge cases more elegantly * Cons: * May incur a higher overhead due to the creation of a new array * Can be slower for very large arrays * **For Loop**: * Pros: * Can be faster for very large arrays, as it avoids creating a new array * More control over iteration and edge cases * Cons: * More verbose code that may be harder to read and maintain * May require more error handling **Library used:** None. **Special JS feature or syntax:** The `map()` function is a built-in JavaScript method, but it does utilize some underlying concepts like closures and dynamic property creation (via the `n => n * 2` arrow function). However, this is considered standard JavaScript features rather than special syntax or advanced features. **Other alternatives:** Other approaches to double each element in an array could include: 1. **Reduce()**: Although not directly applicable here, `reduce()` can be used in conjunction with `map()` for more complex transformations. 2. **Spreading and concatenation**: Using the spread operator (`...`) to create a new array by spreading the original array's elements, followed by concatenation or another method to double each element. These alternatives might offer different performance characteristics depending on the use case and browser support. In conclusion, the test compares two common approaches to transform an array in JavaScript: using `map()` versus a traditional `for` loop. The choice between these methods often depends on the specific requirements of the project, such as code readability, maintainability, and performance.
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