var array = [1, 2, 3, 4, 5, 6, 7, 8]
var itemsToRemove = 2
array = [1, 2, 3, 4, 5, 6, 7, 8].slice(1)
array.splice(0, itemsToRemove)
for (let i = 0 ; i < itemsToRemove ; i++) array.shift()
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
array.slice() | |
array.splice() | |
array.shift() |
Test name | Executions per second |
---|---|
array.slice() | 9772840.0 Ops/sec |
array.splice() | 8012346.0 Ops/sec |
array.shift() | 3797444.5 Ops/sec |
Let's break down the provided benchmark and its test cases.
Benchmark Overview
The benchmark compares the speed of three different approaches to remove two items from the beginning of an array: slice()
, splice()
, and shift()
. The arrays are created with 8 elements, and 2 elements are removed using each approach.
Library and Special Features
Approaches Compared
The three approaches compared are:
array.slice(1)
: This method creates a new array with elements from index 1 to the end of the original array, effectively removing the first two elements.array.splice(0, 2)
: This method removes the specified number of elements from the beginning of the array, in this case, 2 elements.for (let i = 0; i < 2; i++) array.shift()
: This approach uses a loop to remove each element individually using the shift()
method.Pros and Cons
array.slice(1)
:array.splice(0, 2)
:slice()
due to the overhead of removing elements.for (let i = 0; i < 2; i++) array.shift()
:slice()
or splice()
.Other Alternatives
array.concat().slice(2)
(more expensive than slice()
), or using a more complex algorithm like array.map((_, i) => i > 0 ? ... : null)
. However, these alternatives are not directly comparable in this benchmark.Benchmark Interpretation
The benchmark measures the execution speed of each approach. The results indicate that:
array.slice(1)
is the fastest method.array.splice(0, 2)
is slower than slice()
, but faster than the loop-based approach (for (let i = 0; i < 2; i++) array.shift()
).Keep in mind that this benchmark only tests these three specific approaches and does not account for other factors that might affect performance, such as JavaScript engine optimizations or array size.