var strB = "42.034";
var res = +strB;
var res = parseInt(strB);
var res = Number(strB);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
No conversion | |
parseInt | |
Number |
Test name | Executions per second |
---|---|
No conversion | 211762624.0 Ops/sec |
parseInt | 214538688.0 Ops/sec |
Number | 203509312.0 Ops/sec |
Let's dive into explaining the benchmark.
Benchmark Overview
The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The purpose of this benchmark is to compare the performance of three different ways to parse a string representing a floating-point number: parseInt
, Number
, and explicit conversion using the unary plus operator (+
).
Options Being Compared
The benchmark tests three options:
+
). The +
operator attempts to parse the string as an integer if possible, and falls back to parsing it as a floating-point number.parseInt()
function from JavaScript's standard library to parse the string as an integer.Number()
function from JavaScript's standard library to parse the string as a floating-point number.Pros and Cons of Each Approach
NaN
(Not a Number) result if the string is not an integer, requiring additional error handling.+
.parseInt
due to the overhead of parsing the entire string as a float.Library Usage
None of these options use any external libraries, making it easy to run this benchmark in various environments.
Special JavaScript Feature/Syntax
The unary plus operator (+
) is used implicitly to convert the string to a number. This syntax is specific to JavaScript and allows for implicit conversion between strings and numbers.
Other Alternatives
If you want to explore more options or alternatives, here are a few:
Number()
with a radix argument (e.g., Number(strB, 10)
) to parse the string as an integer with a specific radix.Keep in mind that these alternative approaches might have varying degrees of overhead, and may not always outperform the original options.