Number.parseFloat()
BaselineWidely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
TheNumber.parseFloat() static method parses an argument and returns a floating point number. If a number cannot be parsed from the argument, it returnsNaN.
Try it
function circumference(r) { if (Number.isNaN(Number.parseFloat(r))) { return 0; } return parseFloat(r) * 2.0 * Math.PI;}console.log(circumference("4.567abcdefgh"));// Expected output: 28.695307297889173console.log(circumference("abcdefgh"));// Expected output: 0Syntax
js
Number.parseFloat(string)Parameters
stringThe value to parse,coerced to a string. Leadingwhitespace in this argument is ignored.
Return value
A floating point number parsed from the givenstring.
OrNaN when the first non-whitespace character cannot be converted to a number.
Examples
Number.parseFloat vs. parseFloat
This method has the same functionality as the globalparseFloat() function:
js
Number.parseFloat === parseFloat; // trueIts purpose is modularization of globals.
SeeparseFloat() for more detail and examples.
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-number.parsefloat |