Java parse a number in exponential notation

Question

I am trying to do a conversion of a String to integer for which I get a NumberFormatException. The reason is pretty obvious. But I need a workaround here. Following is the sample code.

public class NumberFormatTest {  public static void main(String[] args) {   String num = "9.18E+09";   try{    long val = Long.valueOf(num);   }catch(NumberFormatException ne){    //Try to convert the value to 9180000000 here   }  } } 

I need the logic that goes in the comment section, a generic one would be nice. Thanks.

Answer 1

Use Double.valueOf() and cast the result to long:

Double.valueOf("9.18E+09").longValue() 

Answer 2

BigDecimal bd = new BigDecimal("9.18E+09"); long val = bd.longValue(); 

But this adds overhead, which is not needed with smaller numbers. For numbers that are representable in long, use Joachim Sauer's solution.