// Params:
const arr = [1, 2, 3, 4];
const index = 3;
const newItem = 5;
// Steps:
// 1. Create new array from the original one at given index
let copy = [];
for (let i = 0; i < index; i++) {
copy[copy.length] = arr[i];
}
// 2. Add new item to the copy
copy[index] = newItem;
// 3. Get the rest of the original array
let rest = [];
for (let i = index; i < arr.length; i++) {
rest[rest.length] = arr[i];
}
// 4. Merge the two arrays
for (let i = 0; i < rest.length; i++) {
copy[copy.length] = rest[i];
}
// 5. Print the merged array
console.log(copy);
// Params:
const arr = [1, 2, 3, 4];
const index = 3;
const newItem = 5;
// Steps:
// 1. Create new array from the original one at given index
let start = arr.slice(0, index);
// 2. Add new item to the copy
start.push(newItem);
// 3. Get the rest of the original array
let end = arr.slice(index);
// 4. Print the merged array
console.log(start.concat(end));
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
For-loop approach test | |
Native functions test |
Test name | Executions per second |
---|---|
For-loop approach test | 34778.5 Ops/sec |
Native functions test | 36504.1 Ops/sec |
Let's dive into the world of JavaScript microbenchmarks.
What is being tested?
The provided JSON represents a benchmark that tests two approaches to inserting a value at a certain index in an array:
Options being compared
The benchmark compares the performance of these two approaches:
Pros and cons of each approach
Library used
There is no explicit library mentioned in the benchmark definition or test cases. However, it's likely that the console.log
function is used to print the results of the array manipulation.
Special JS feature or syntax
There are some special features and syntax used in this benchmark:
// Params:\r\nconst arr = [1, 2, 3, 4];
) for string interpolation.for
loops (specifically, a traditional loop with index variables) to iterate over the array.Other alternatives
If the developers wanted to explore alternative approaches, they might consider:
Array.prototype.splice
or Array.prototype.concat
, to manipulate the array.Keep in mind that these alternatives would likely require significant changes to the benchmark definition and test cases.