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slice vs spread v.2
(version: 0)
Comparing performance of:
slice vs spread
Created:
6 years ago
by:
Guest
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Tests:
slice
var params = [ "hello", true, 7, 12, "Yay", "hateSlice", "1337", false, "SomethingElse", "hello", true, 7, 12, "Yay", "hateSlice", "1337", false, "SomethingElse"]; var other = [ 1, 2 ].slice();
spread
var params = [ "hello", true, 7, 12, "Yay", "hateSlice", "1337", false, "SomethingElse", "hello", true, 7, 12, "Yay", "hateSlice", "1337", false, "SomethingElse"]; var other = [ ...params ]
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Suite status:
<idle, ready to run>
Run tests (2)
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Test case name
Result
slice
spread
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net. **Benchmark Overview** The benchmark is designed to compare two approaches for creating an array copy: the `slice()` method and the spread operator (`[...])`. The test cases are identical, except for the method used to create the array copy. **Options Compared** Two options are compared: 1. **`slice()` method**: This method creates a shallow copy of an array by referencing the original elements. 2. **Spread Operator (`[...]`)**: This operator creates a new array by copying the elements from the original array. **Pros and Cons** * **`slice()` method**: + Pros: - Fast, as it only needs to create a reference to the original array. - Memory-efficient, as it doesn't allocate new memory for the copy. + Cons: - Can lead to unexpected behavior if the original array is modified while the copy is in use (since both references point to the same memory location). - May not work as expected with nested arrays or objects, as `slice()` only creates a shallow copy. * **Spread Operator (`[...]`)**: + Pros: - Creates a deep copy of the array, ensuring that modifications to the original don't affect the copy. - Works well with nested arrays and objects, as it recursively creates new copies of all elements. + Cons: - Slower than `slice()`, since it needs to allocate new memory for each element. - Can be more memory-intensive, especially for large arrays. **Library/Features Used** None are explicitly mentioned in the benchmark definition or test cases. However, it's worth noting that modern JavaScript engines (like V8) have optimized implementations of both `slice()` and the spread operator. **Special JS Features/Syntax** None are used or mentioned in this benchmark. **Other Alternatives** If you're interested in exploring alternative methods for array copying, consider: 1. **`Array.prototype.slice.call()`**: This method creates a new array by calling the `slice()` method on an object that has been coerced to an array. 2. **`Array.from()`**: This method creates a new array from an iterable or an array-like object. 3. **`Array.prototype.map()`**: While not exactly an array copying method, `map()` can be used to create a new array by mapping over the original array. Keep in mind that these alternatives may have different performance characteristics and memory usage compared to `slice()` and the spread operator. I hope this explanation helps you understand the JavaScript microbenchmark on MeasureThat.net!
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