MSDN Library

parseFloat Function (JavaScript)

Returns a floating-point number converted from a string.


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

The parseFloat function 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.

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

You can test for NaN using the isNaN function.

Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards. See Version Information.

Applies To: Global Object (JavaScript)

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