The parseFloat()
function parses an argument and returns a floating-point number.
Example
const stringDate = "23.9";
// parse the string to float value
let floatDate = parseFloat(stringDate);
console.log(floatDate)
// Output: 23.9
parseFloat() Syntax
The syntax of the parseFloat()
function is:
parseFloat(string)
parseFloat() Parameters
The parseFloat()
function takes in:
- string - The value to parse. If it is not a string, it is converted to one using
ToString
abstract operation.
Note: Leading whitespace characters are ignored.
parseFloat() Return Value
- Returns a floating-point number parsed from the given string.
- Returns
NaN
when the first non-whitespace character can't be converted to a number.
Example: Using parseFloat()
console.log(parseFloat(" 10 ")); // 10
console.log(parseFloat(" 3.14seconds")); // 3.14
console.log(parseFloat("314e-2")); // 3.14
// argument can be anything as long as it has toString or valueOf
const obj = {
toString: () => "127.0.0.1",
};
console.log(parseFloat(obj)); // 127
console.log(parseFloat("JavaScript")); // NaN
// BigInt values lose precision
console.log(parseFloat("464546416543075614n")); // 464546416543075600
Output
10 3.14 3.14 127 NaN 464546416543075600
Notes:
parseFloat()
will parse non-string objects if they have atoString
orvalueOf
method.parseFloat()
stops converting a string to float when it encounters a non-numeric character.
Recommended Reading: Javascript parseInt()