“Odwrotna liczba ujemna” Kod odpowiedzi

Odwrotna liczba ujemna

Number -- Reverse negative number
Write a return method that can reverse negative number and return it as int
 
Solution:
public static int reverseNum(int  num) {
String str = new StringBuilder(""+num).reverse().toString();
if(num < 0) {
str = "-"+str.substring(0, str.length()-1);
}
return Integer.valueOf(str);
}