Number.parseFloat()
Baseline
Widely available
This feature is well established and works across many devices and browser versions. Itās been available across browsers since āØSeptember 2015ā©.
The Number.parseFloat() static method parses an argument and returns a floating point number. If a number cannot be parsed from the argument, it returns NaN.
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: 28.695307297889173
console.log(circumference("abcdefgh"));
// Expected output: 0
Syntax
js
Number.parseFloat(string)
Parameters
string-
The value to parse, coerced to a string. Leading whitespace in this argument is ignored.
Return value
A floating point number parsed from the given string.
Or NaN 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 global parseFloat() function:
js
Number.parseFloat === parseFloat; // true
Its purpose is modularization of globals.
See parseFloat() for more detail and examples.
Specifications
| Specification |
|---|
| ECMAScriptĀ® 2026 LanguageĀ Specification # sec-number.parsefloat |