<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
var x = 5.236;
for (var i = 0; i < 1000; i++) {
_.round(x,2);
}
for (var i = 0; i < 1000; i++) {
x.toFixed(2);
}
for (var i = 0; i < 1000; i++) {
parseFloat(x).toFixed(2);
}
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Round floating number using lodash round function | |
Round floating number using toFixed() | |
Round floating number using toFixed() and parseFloat |
Test name | Executions per second |
---|---|
Round floating number using lodash round function | 392.8 Ops/sec |
Round floating number using toFixed() | 1628.3 Ops/sec |
Round floating number using toFixed() and parseFloat | 1047.6 Ops/sec |
Let's break down the provided benchmark and explain what is being tested.
Benchmark Overview
The benchmark compares three different approaches to rounding a floating-point number:
lodash.round
(using the Lodash library)toFixed()
(JavaScript native function)parseFloat().toFixed()
(combination of two functions)Options Compared
The options compared are:
lodash.round(x, 2)
: rounds the input x
to 2 decimal places using the Lodash library.x.toFixed(2)
: rounds the input x
to 2 decimal places using JavaScript's toFixed()
function.parseFloat(x).toFixed(2)
: first converts x
to a floating-point number using parseFloat()
, and then rounds it to 2 decimal places using toFixed()
.Pros and Cons of Each Approach
round()
: This approach is specific to the Lodash library, which means it requires an additional dependency. However, it provides a more explicit and controlled rounding process.toFixed()
: This approach is part of the JavaScript standard library and is widely supported. It's also very concise and easy to read.parseFloat().toFixed()
: This approach combines the benefits of both toFixed()
and parseFloat()
. However, it's slightly more verbose than using just toFixed()
.Library and Purpose
The Lodash library is a popular JavaScript utility library that provides various functions for tasks such as string manipulation, array manipulation, and more. The round()
function in particular is designed to round numbers to a specified decimal place, making it a convenient option for this benchmark.
Special JS Features or Syntax
There are no special JS features or syntax used in this benchmark. However, it's worth noting that the use of var
instead of let
or const
is not modern JavaScript practice and can lead to issues with variable scope and hoisting.
Other Alternatives
For rounding floating-point numbers in JavaScript, other alternatives include:
Math.round()
function, which rounds to the nearest integer.Keep in mind that the choice of rounding approach depends on the specific requirements and constraints of your project.