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spread vs concat vs unshift1
(version: 0)
spread vs concat vs unshift
Comparing performance of:
arrayUnshift123 vs arrayConcat123 vs arraySpread123
Created:
2 years ago
by:
Guest
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Script Preparation code:
var array = [1,2,3];
Tests:
arrayUnshift123
array.unshift(0);
arrayConcat123
array = [0].concat(array)
arraySpread123
array = [0, ...array]
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
Previous results
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Test case name
Result
arrayUnshift123
arrayConcat123
arraySpread123
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 the provided benchmark. **Benchmark Overview** The test compares three different ways to add an element to the beginning of an array: `unshift()`, `concat()` followed by slicing, and the spread operator (`...`). The benchmark is designed to measure which approach is the fastest in modern web browsers. **Options Compared** 1. **`unshift()`**: This method adds a new element to the end of an array and then shifts all subsequent elements one position to the right. 2. **`concat()` followed by slicing**: This method concatenates two arrays using `concat()`, which returns a new array, and then slices the resulting array from the beginning to get the desired result. 3. **Spread operator (`...`)**: This is a newer JavaScript syntax that allows creating an array from an iterable (such as another array) using the spread operator. **Pros and Cons of Each Approach** 1. **`unshift()`**: * Pros: Generally faster than `concat()` followed by slicing, since it modifies the original array in place. * Cons: Can be slower if the array is very large, because it creates a new array with all elements shifted down by one index. 2. **`concat()` followed by slicing**: * Pros: More predictable performance, as it creates a new array without modifying the original. * Cons: Can be slower than `unshift()`, since creating a new array requires more memory allocation and copying of data. 3. **Spread operator (`...`)**: * Pros: Fast and efficient, since it only creates a new array reference without modifying the original. * Cons: Requires modern browsers that support this syntax (which is generally the case in web development). **Library or Special JS Feature** In this benchmark, no libraries are used. The tests focus solely on the performance of these three approaches. **Special JS Feature (None)** There are no special JavaScript features being tested here. **Other Alternatives** If you're looking for alternative ways to add an element to the beginning of an array, you could consider using other methods, such as: * Using a data structure like a linked list or a deque, which allows efficient insertion at both ends. * Utilizing a library that provides optimized array manipulation functions, such as `lodash`. * Using a different programming paradigm, like functional programming with immutable data structures. However, these alternatives are not being tested in this benchmark.
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