<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++) {
Number(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 | 2657.8 Ops/sec |
Round floating number using toFixed() | 8621.3 Ops/sec |
Round floating number using toFixed() and parseFloat | 3907.9 Ops/sec |
Let's dive into the explanation of the provided benchmark.
Benchmark Overview
The benchmark is designed to compare three approaches for rounding a floating-point number: lodash.round
, toFixed()
, and toFixed()
followed by parseFloat
. The goal is to determine which approach is the most efficient.
Options Compared
lodash.round
: A function from the Lodash library that rounds a number to a specified decimal place.toFixed(2)
: A JavaScript method that formats a number as a fixed-point string with a specified number of decimals.toFixed(2) + parseFloat()
: Combining toFixed(2)
with parseFloat()
to achieve similar rounding behavior.Pros and Cons
toFixed(2)
:toFixed(2) + parseFloat()
:lodash.round
, but avoids the dependency on Lodash.Library - lodash
Lodash is a popular JavaScript utility library that provides a wide range of functions for tasks like array manipulation, object transformation, and more. In this benchmark, _lodash.round()
is used to round floating-point numbers.
Special JS Feature/Syntax - toFixed()
toFixed(2)
uses the ECMAScript 5 (ES5) method for formatting numbers as fixed-point strings. This syntax is widely supported across modern browsers and JavaScript engines.
Other Alternatives
If you're looking for alternative rounding methods, consider:
Number.EPSILON
(approximately 5e-324) to determine the smallest representable floating-point value.When choosing an approach, weigh factors like performance, precision, and maintainability. In this benchmark, toFixed(2)
emerges as a lightweight and straightforward solution, while _lodash.round()
offers more robustness and flexibility. The combined approach of toFixed(2)
+ parseFloat()
strikes a balance between these considerations.