How to convert an hexadecimal string to a double?

Question

I\'m getting the hexadecimal values of range 0x0000 to 0x01c2 from BLE to my phone a as String. In order to plot it in a graph, I have to convert it into

Answer 1

Your value isn't a hex representation of an IEEE-754 floating point value - it's just an integer. So just parse it as an integer, after removing the leading "0x" prefix:

public class Test {
    public static void main(String[] args) {
        String text = "0x009a";

        // Remove the leading "0x". You may want to add validation
        // that the string really does start with 0x
        String textWithoutPrefix = text.substring(2);
        short value = Short.parseShort(textWithoutPrefix, 16);
        System.out.println(value);
    }
}

If you really need a double elsewhere, you can just implicitly convert:

short value = ...;
double valueAsDouble = value;

... but I'd try to avoid doing so unless you really need to.