The required numString argument is a string that contains a floating-point number.

The parseFloat method returns a numerical value equal to the number contained in numString. If no prefix of numString can be successfully parsed into a floating-point number, NaN (not a number) is returned.

 	Copy Code
parseFloat("abc") // Returns NaN. parseFloat("1.2abc") // Returns 1.2.

You can test for NaN using the isNaN method.

Version 1

Applies To: Global Object (JScript 5.6)

Reference