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javascript static method

Number.parseFloat()

View on MDN ↗

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.

Interactive exampleOpen the canonical MDN source to run this embedded demo.
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

Number.parseFloat(string)

Parameters

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:

Number.parseFloat === parseFloat; // true

Its purpose is modularization of globals.

See parseFloat() for more detail and examples.

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also