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Test splice
(version: 0)
Comparing performance of:
slice vs shift
Created:
9 years ago
by:
Guest
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Tests:
slice
function slasher(arr, howMany) { // Return string after the amount chopped off. return arr.slice(howMany); } slasher([1, 2, 3], 9);
shift
function slasher(arr, howMany) { // it doesn't always pay to be first for (var i = 0; i < howMany; i++) { arr.shift(); } return arr; } slasher([1, 2, 3], 9);
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Suite status:
<idle, ready to run>
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Test case name
Result
slice
shift
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'll provide an explanation of the benchmark, its options, pros and cons, and other considerations. **Benchmark Overview** The MeasureThat.net website allows users to create and run JavaScript microbenchmarks. The provided JSON represents a simple benchmark with two test cases: "slice" and "shift". The benchmark is designed to measure the performance difference between using `Array.prototype.slice()` and `Array.prototype.shift()` to remove elements from an array. **Benchmark Definition** The benchmark definition is a string containing the JavaScript function that will be executed during the benchmark. In this case, there are two test cases: 1. "slice": ```javascript function slasher(arr, howMany) { return arr.slice(howMany); } ``` This function takes an array `arr` and a number `howMany` as arguments. It returns a new array containing only the elements that were not removed. 2. "shift": ```javascript function slasher(arr, howMany) { for (var i = 0; i < howMany; i++) { arr.shift(); } return arr; } ``` This function takes an array `arr` and a number `howMany` as arguments. It removes the first `howMany` elements from the array using `Array.prototype.shift()` and returns the modified array. **Options Compared** The two test cases compare the performance of the following options: 1. Using `Array.prototype.slice()`: This method creates a new array containing only the elements that were not removed. 2. Using `Array.prototype.shift()`: This method removes the first element from the array, shifting all subsequent elements down. **Pros and Cons** * **Using `Array.prototype.slice()`**: + Pros: Creates a new array, which can be more efficient for certain use cases (e.g., when working with large arrays). + Cons: Can be slower than using `shift()`, especially for small arrays. * **Using `Array.prototype.shift()`**: + Pros: Faster than `slice()` for small arrays, as it only requires a single operation to remove the first element. + Cons: Modifies the original array, which can have unintended consequences if not used carefully. **Other Considerations** * The benchmark does not account for memory allocation or deallocation, which can affect performance in certain scenarios. For example, creating a new array using `slice()` may allocate more memory than using `shift()`. * The benchmark only measures the execution time of the two test cases and does not consider other factors that may impact performance, such as caching or optimization. **Libraries Used** None are explicitly mentioned in the provided JSON. However, it is worth noting that some libraries (e.g., Lodash) provide optimized implementations of `slice()` and `shift()`, which may affect performance. **Special JS Features/Syntax** There are no special JavaScript features or syntax used in this benchmark. The code is straightforward and easy to understand.
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