var arr = Array.from(Array(10000).keys());
arr.slice(-1)[0];
arr[arr.length-1];
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
`Array.slice(-1)[0]` | |
`Array[Array.length]` |
Test name | Executions per second |
---|---|
`Array.slice(-1)[0]` | 10088678.0 Ops/sec |
`Array[Array.length]` | 7853367.0 Ops/sec |
Let's break down the provided benchmark definition and test cases.
What is tested?
The main goal of this benchmark is to compare two approaches for accessing the last element of an array in JavaScript:
Array.slice(-1)[0]
arr[arr.length-1]
In other words, both methods aim to retrieve the last element of a large array (arr
with 10,000 elements). The benchmark measures which method performs better.
Options compared
We have two options being compared:
a. Dynamic property access: arr[arr.length-1]
b. Method chaining with slice(): Array.slice(-1)[0]
Both methods are used to access the last element of an array, but they differ in how they achieve it.
Pros and Cons
Dynamic Property Access (arr[arr.length-1]
)
Pros:
Cons:
Method Chaining with Slice() (Array.slice(-1)[0]
)
Pros:
Cons:
arr.length-1
, Array.slice(-1)
).Library usage
There is no library explicitly mentioned in the benchmark definition. However, it's worth noting that some libraries like Lodash might provide similar functionality or alternatives to these approaches.
Special JS feature/syntax
None are explicitly mentioned. The syntax used here is standard JavaScript.
Other considerations
arr
is created using Array.from(Array(10000).keys())
, which generates an array of 10,000 numbers from 0 to 9,999.Other alternatives
If you're interested in exploring other approaches or optimizing these methods further, consider looking into:
Array.prototype.at()
(supported in modern browsers and Node.js), which is a more concise and expressive way to access array elements.Keep in mind that optimizations should be carefully evaluated for their impact on readability, maintainability, and overall performance.