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destructure vs pop and clone
(version: 0)
Comparing performance of:
destruc vs clone + pop
Created:
3 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
var arr = [] for (let i = 0; i < 50; i++) { arr.push(i); }
Tests:
destruc
var [firstElem, ...rest] = arr;
clone + pop
var clone = [...arr]; var lastElem = arr.pop();
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
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Test case name
Result
destruc
clone + pop
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'd be happy to help explain what's being tested in this benchmark. The provided JSON represents a JavaScript microbenchmark that measures the performance difference between two approaches: destructuring assignment and using `Array.prototype.pop()` followed by cloning the array. **Script Preparation Code** The script preparation code creates an array `arr` with 50 elements, where each element is a number from 0 to 49. This array will be used as the input for both benchmarking approaches. **Benchmark Definition JSON** The benchmark definition contains two test cases: 1. **Destructuring assignment**: `"var [firstElem, ...rest] = arr;"` This approach uses destructuring assignment to extract the first element (`firstElem`) and the rest of the elements (`rest`) from the array `arr`. The resulting values are stored in separate variables. 2. **Using `Array.prototype.pop()` followed by cloning**: `"var clone = [...arr];\r\nvar lastElem = arr.pop();"` This approach creates a shallow copy of the array `arr` using the spread operator (`[...arr]`). It then removes and stores the last element from the original array using `Array.prototype.pop()`, leaving an empty array with all elements except the first one. **Comparison** The benchmark compares the performance of these two approaches: 1. **Destructuring assignment**: This approach is generally faster because it only requires a single operation to extract the desired values, without creating intermediate arrays. 2. **Using `Array.prototype.pop()` followed by cloning**: This approach is slower because it involves two operations: popping an element from the array and then cloning the entire array. **Pros and Cons** 1. **Destructuring assignment**: * Pros: Faster, more concise, and easier to read. * Cons: May not be as effective for extracting all elements or modifying the original array. 2. **Using `Array.prototype.pop()` followed by cloning**: * Pros: Can be used to extract a single element while leaving the rest of the array intact. * Cons: Slower, more verbose, and may consume more memory. Other considerations: 1. **Library usage**: Neither approach uses any external libraries, making them language-agnostic. 2. **Special JS features or syntax**: There are no special JS features or syntax used in this benchmark. 3. **Alternatives**: * For destructuring assignment, you can also use `let [firstElem] = arr;` to extract only the first element. * For using `Array.prototype.pop()` followed by cloning, you could use `var lastElem = arr[arr.length - 1];` to extract the last element without cloning. In summary, this benchmark measures the performance difference between two approaches for extracting elements from an array: destructuring assignment and using `Array.prototype.pop()` followed by cloning. The results indicate that destructuring assignment is generally faster, making it a more efficient choice when possible.
Related benchmarks:
Slice vs spread and Pop
Destructure first elem vs pop
Slice vs Pop copy
Cloning an array
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