Formatting doubles in a toString return

[S Gregg]

Hey guys,

I'm new here but think I'm going to become a regular visitor now that I started my Java class. I am having trouble with one of my assignments, I have a toString method that is supposed to print out information on a triangle. My problem is I am trying to format the numbers to 2 or 3 decimal places but having some difficulty. Here is my toString method

   
public String toString() {
        return ("The points you chose for the triangle were " + pointA + ", "
                + pointB + " and " + pointC + "\nThe length of the sides of" +
                " the triangle were " + length1 + ", " + length2 + " and "
                + length3 + "\nThe perimeter of the triangle is " + perimeter
                + "\nThe area of the triangle is " + area); 

    } 

The call to the toString method looks like this

System.out.println(triangle1);

The length variables as well as the perimeter and area are the ones that are of type double and are the ones I'm trying to round off to 3dp.

Any help is greatly appreciated.

[Rahul P Kumar]

visit this link

[Rob Spoor]

Rahul.p Kumar wrote:visit this link

That method is used internally already by the code S Gregg posted; String concatenation already converts all non-Strings using one of the overloaded String.valueOf methods.

S Gregg, check out String.format / java.util.Formatter or java.text.NumberFormat.

[Campbell Ritchie]

And welcome to JavaRanch

Agree with Rob; my preference would be to use Rob's first suggestion. That is very closely related to the Formatter methods; I think it simply creates a Formatter object and passes the arguments on to that.