const basicData = [{id: 1}, {id: 2}, {id: 3}];
const finalData = [basicData, {id: 4}];
var basicData = [{id: 1}, {id: 2}, {id: 3}];
basicData.push({id: 4});
var basicData = [{id: 1}, {id: 2}, {id: 3}];
basicData[basicData.length] = {id: 4};
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Using spread operator | |
Using push function | |
Add to last index of array |
Test name | Executions per second |
---|---|
Using spread operator | 17787580.0 Ops/sec |
Using push function | 24113120.0 Ops/sec |
Add to last index of array | 23894220.0 Ops/sec |
Let's dive into the benchmark test and its various components.
Benchmark Overview
The provided JSON represents a JavaScript microbenchmark test on MeasureThat.net, which compares three different approaches for adding an element to an array: using the spread operator ([...]
), the push()
function, and accessing the last index of the array directly (array[lastIndex]
).
Test Cases
There are three individual test cases:
const basicData = [{id: 1}, {id: 2}, {id: 3}];
const finalData = [...basicData, {id: 4}];
The ...
operator creates a new array by copying all elements from the original array (basicData
) and adding the new element at the end.
push()
function to add an element to an array.var basicData = [{id: 1}, {id: 2}, {id: 3}];
basicData.push({id: 4});
The push()
function adds a new element at the end of the array.
array[lastIndex]
) to add an element to an array.var basicData = [{id: 1}, {id: 2}, {id: 3}];
basicData[basicData.length] = {id: 4};
This approach assumes that the last index of the array is known and used directly.
Options Compared
The three test cases compare different approaches for adding an element to an array:
[...]
): Creates a new array by copying all elements from the original array and adding the new element at the end.array[lastIndex]
): Uses direct indexing to add an element at the known last index of the array.Pros and Cons
Here's a brief summary of the pros and cons of each approach:
[...]
):array[lastIndex]
):Libraries Used
There are no libraries explicitly mentioned in the benchmark test cases. However, it's worth noting that using external libraries like Lodash or Ramda might provide additional functionality for array manipulation and testing.
Special JS Features/Syntax
The benchmark test does not use any special JavaScript features or syntax beyond the standard language features. If you're interested in exploring more advanced topics, MeasureThat.net provides a wide range of benchmarks that cover various aspects of JavaScript performance.
Alternatives
If you'd like to explore alternative approaches for adding an element to an array, consider the following:
+
Array.prototype.shift()`: Reverses the array and then shifts one element off the end to add a new element.Keep in mind that performance optimization is highly dependent on the specific use case and environment. These alternatives might not always provide better performance or readability than the original approaches used in the benchmark test.