Remove values off the end of a string

I have a number I got off a exploration map and am storing it in storage but I want to remove the "d" denoting double off the end. i.e. instead of "1430.0d" I just want "1430" the problem is the size of the value changes .i.e could be "330.0d" so I can't just have a set start and end, any way to do this?