var arr = []
for (var i = 0; i < 1000000; i++) {
arr.unshift(42)
}
for (var i = 0; i < 1000000; i++) {
arr.push(42)
}
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
.unshift() | |
.push() |
Test name | Executions per second |
---|---|
.unshift() | 0.4 Ops/sec |
.push() | 23.6 Ops/sec |
Let's break down the provided JSON and explain what is tested, compared, and their pros and cons.
Benchmark Definition
The benchmark is comparing the performance of two approaches: arr.push(42)
and arr.unshift(42)
, on an empty array var arr = []
. The goal is to measure which approach is faster when adding 1 million elements to the array.
Script Preparation Code
The script preparation code is a simple initialization of the array var arr = []
.
Html Preparation Code
There is no HTML preparation code, which means that the benchmark only tests the JavaScript performance and does not consider any DOM-related overhead or other non-JavaScript aspects.
Individual Test Cases
There are two test cases:
.unshift()
: This test case uses the arr.unshift(42)
approach, which adds an element to the beginning of the array..push()
: This test case uses the arr.push(42)
approach, which adds an element to the end of the array.Libraries and Special JS Features
There are no libraries used in this benchmark. However, it's worth noting that both .unshift()
and .push()
methods rely on JavaScript's built-in array data structure, so there is no special JS feature or syntax involved.
Pros and Cons of Each Approach
.unshift()
:.push()
:Other Considerations
When deciding between .unshift()
and .push()
, consider the typical use case:
arr.unshift()
.arr.push()
.Other Alternatives
If you need to optimize array operations further, consider using other approaches, such as:
Array.prototype.slice()
and Array.prototype.splice()
, which can be more efficient than direct array manipulation.Keep in mind that the best approach depends on your specific use case and requirements.