Mozilla Developer NetworkSummary
Parses a string argument and returns a floating point number.
| Core Global Method | |
|---|---|
| Implemented in | JavaScript ? |
| ECMAScript Edition | ECMAScript ? |
Syntax
parseFloat(string) Parameters
-
string - A string that represents the value you want to parse.
Description
parseFloat is a top-level function and is not associated with any object.
parseFloat parses its argument, a string, and returns a floating point number. If it encounters a character other than a sign (+ or -), numeral (0-9), a decimal point, or an exponent, it returns the value up to that point and ignores that character and all succeeding characters. Leading and trailing spaces are allowed.
If the first character cannot be converted to a number, parseFloat returns NaN.
For arithmetic purposes, the NaN value is not a number in any radix. You can call the isNaN function to determine if the result of parseFloat is NaN. If NaN is passed on to arithmetic operations, the operation results will also be NaN.
Examples
Example: parseFloat returning a number
The following examples all return 3.14
parseFloat("3.14");
parseFloat("314e-2");
parseFloat("0.0314E+2");
parseFloat("3.14more non-digit characters");
Example: parseFloat returning NaN
The following example returns NaN
parseFloat("FF2");
