Rounding

public double round (double num, int digit)
{
double num2 = num * Math.pow (10, digit);
double num3 = (num2 - ((int) num2)) * 10;
num2 = ((int) num2);
if (num3 >= 5)
num2++;
return num2 /= Math.pow (10, digit);
}

• Put this code outside your constructor, but inside the class.
• This rounds doubles.
• Inside your code, when you wish to round something, put round(variableName, 2) if your want the variable to have 2 digits. Print round(variableName, 0) if you don't want any decimal places.
• Watch the class closing bracket. Students like to delete it! Don't!

For example:

• System.out.println("The cost is $"+ round(total_cost,2)+".");
• System.out.println("The total is: "+round(grandTotal,0));

Here is an entire program so that you can try it out:

public class rounding
   {
   public static void main (String args [])
   {
   new rounding ();
   }

 public rounding ()
   {
   double x = 5;
   double y = 9;
   double percent = x / y * 100;
   System.out.println ("Pre-rounding: " + percent);
   System.out.println ("As a cost: $" + round (percent, 2) + ".");
   System.out.println ("As a percent: " + round (percent, 0) + "%");
   }

 public double round (double num, int digit)
   {
   double num2 = num * Math.pow (10, digit);
   double num3 = (num2 - ((int) num2)) * 10;
   num2 = ((int) num2);
   if (num3 >= 5)
   num2++;
   return num2 /= Math.pow (10, digit);
   }
   } //class closing bracket!