parseFloat (JavaScript)

Parses a string and returns a floating point number.

Defined in

Top-level functions (JavaScript)

Syntax

parseFloat(string)
Parameter Description
string A string that represents a floating point number in fixed or exponential notation. Truncation occurs at a character that is not correct floating point notation. Leading and trailing spaces are legal.

Usage

If the first character of string is not legal for a floating point number, the result is the value NaN. See isNaN (JavaScript).

Examples

This example creates floating point numbers and tests them to make sure they are valid numbers.
function p(stuff) {
	print("<<<" + stuff + ">>>");
}

var x = parseFloat("3.14");
if (isNaN(x))
	p("x is not a number");
else
	p("x = " + x);
// <<<x = 3.14>>>

var x = parseFloat("314e-2");
if (isNaN(x))
	p("x is not a number");
else
	p("x = " + x);
// <<<x = 3.14>>>

var x = parseFloat("0.0314e+2");
if (isNaN(x))
	p("x is not a number");
else
	p("x = " + x);
// <<<x = 3.14>>>

var x = parseFloat("f0.0314e+2");
if (isNaN(x))
	p("x is not a number");
else
	p("x = " + x);
// <<<x is not a number>>>