JavaScript Reference/Javascript Methods/parseFloat
"parseFloat()" Example
<html>
<body>
<button onclick="alert(parseFloat("12.34"));">Number</button>
<button onclick="alert(parseFloat("Hello"));">NaN</button>
</body>
</html>
"parseFloat()" Syntax, Parameters and Note
Note:
Converts string to a floating-point number.
Returns a floating-point number if value supplied is numeric, or
NaN if value supplied is not numeric.
Syntax:
parseFloat(param1)
Parameters:
param1 Required; the string to be evaluated.