function m(l1, l2) {
var u = [];
for (var i = 0; i < l1.length; i++) {
u.push(l1[i]);
}
for (var j = 0; j < l2.length; j++) {
var dupe = false;
for (var i = 0; i < l1.length; i++) {
if (l1[i] === l2[j]) {
dupe = true;
}
}
if (!dupe) {
u.push(l2[j]);
}
}
return u;
}
function n(l1, l2) {
let combined = [].concat(l1, l2);
return [new Set(combined)];
}
Array.prototype.unique = function() {
var a = this.concat();
for(var i=0; i<a.length; ++i) {
for(var j=i+1; j<a.length; ++j) {
if(a[i] === a[j])
a.splice(j--, 1);
}
}
return a;
};
function usingForEach(l1,l2){
let u = []
l1.forEach(function(item){
u.push(item);
});
l2.forEach(function(item){
if(u.indexOf(item)<0)
u.push(item);
});
return u;
}
var a = [1, 2, 3, 4, 5];
var b = [3, 3, 4, 5, 5, 6, 7];
var testM = m(a, b);
var testN = n(a, b);
var testUnique = a.concat(b).unique();
var y = usingForEach(a,b);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
m | |
n | |
unique | |
y |
Test name | Executions per second |
---|---|
m | 3256162.5 Ops/sec |
n | 959444.9 Ops/sec |
unique | 1648508.5 Ops/sec |
y | 3039958.0 Ops/sec |
Let's dive into the world of JavaScript microbenchmarks.
Benchmark Definition JSON Explanation
The provided JSON represents a benchmark definition for measuring the performance of JavaScript functions. It contains two main sections:
m(l1, l2)
: This function takes two arrays as input and returns a new array with duplicates removed.n(l1, l2)
: This function concatenates the input arrays and returns a new array with duplicates removed using the Set
data structure.usingForEach(l1,l2)
: This function iterates over both input arrays and adds unique elements to a result array.Array.prototype.unique = ...
: This is a method that removes duplicates from an array in-place. However, it's not directly applicable to the benchmark as it modifies the original array.Options Compared
The benchmark compares four different approaches to remove duplicates from two input arrays:
m(l1, l2)
: Uses a nested loop to iterate over both arrays and add elements to a result array.n(l1, l2)
: Concatenates the input arrays using the spread operator ([...new Set(combined)]
) to remove duplicates.usingForEach(l1,l2)
: Iterates over both input arrays and adds unique elements to a result array using the forEach
method.Array.prototype.unique = ...
: This is not directly applicable to the benchmark, but it's included for comparison purposes.Pros and Cons of Each Approach
Here's a brief analysis of each approach:
Set
data structure, fast execution.Set
.Library and Special JS Features
The Set
data structure is used in the n(l1, l2)
implementation. Set
is a built-in JavaScript object that automatically removes duplicates from its elements.
There are no special JavaScript features or syntax mentioned in the benchmark definition.
Other Alternatives
If you're interested in exploring alternative approaches to removing duplicates from arrays, here are a few options:
filter
method to remove elements that don't match a condition, followed by the map
method to create a new array with unique elements.reduce
method to iterate over an array and accumulate unique elements in a result array.Keep in mind that each approach has its pros and cons, and the best choice depends on your specific use case and performance requirements.