question: protected static String doubleToString ( double num ) { long whole = ( long ) num ; if ( whole == Long . MAX_VALUE || whole == Long . MIN_VALUE ) { return Double . toString ( whole ) ; } double fract = Math . abs ( num - whole ) ; String res = Long . toString ( whole ) ; if ( fract != 0.0 ) { String f2s = Double . toString ( fract + 1.0 ) ; res += f2s . substring ( 1 ) ; } return res ; }
target:  Converts a double to string with maximum precision.