 |  |  |  |  |  |  |  |
Trouble with area
Thread Solved |
I have been trying to build a Java program to prompt the user to enter the radius of a circle and the diameter, circumference, and area will be output through a "System.out.printf" statement. I can get the program to prompt for the radius and it will display the diameter, but will not identify the Area or Circumference. I keep getting an error with the Math variable. What could be wrong with this code for Area:
System.out.printf("Area is %d\n", (x * x * math.PI) );
System.out.printf("Area is %d\n", (x * x * math.PI) );
•
•
Join Date: Jun 2009
Posts: 830
Reputation: 
Solved Threads: 94
Practically a Posting Shark
Ahem!
Given only radius gives you all the other data. No need to input.
Circumference = 2 * PI * r
Area = PI * r * r
etc.
I'm also assuming your x is entered as a Floating-Point value.
Given only radius gives you all the other data. No need to input.
Circumference = 2 * PI * r
Area = PI * r * r
etc.
I'm also assuming your x is entered as a Floating-Point value.
JAVA Syntax (Toggle Plain Text)
Last edited by wildgoose; Jul 2nd, 2009 at 6:44 pm. Reason: error
Thanks, that really cleared up my format for the Area and Circumference, but I am still getting an error for diameter. Honestly, I do not know why. I have eliminated one problem by capitalizing the "M" in Math.PI, but can't get over the diameter issue.
•
•
Join Date: Jun 2009
Posts: 830
Reputation:
Solved Threads: 94
Practically a Posting Shark
Please post your code!
•
•
Join Date: Sep 2008
Posts: 1,563
Reputation:
Solved Threads: 196
And also post what error you are getting. If you are successfully reading in the radius, then 2 * radius should give you the diameter without problems as long as the radius is declared as the correct type (i.e. float or double).
Last edited by BestJewSinceJC; Jul 6th, 2009 at 9:45 pm.
Out.
•
•
•
•
Originally Posted by BestJewSinceJC 
And also post what error you are getting. If you are successfully reading in the radius, then 2 * radius should give you the diameter without problems as long as the radius is declared as the correct type (i.e. float or double).
"Diameter is Exception in thread "main" java.util.IllegalFormatConversionException: f != java.lang.Integer"
System.out.print( "declare radius of circle: " ); // prompt for input
x = input.nextInt(); // read first integer
//display results
System.out.printf("Area is %f\n", (x * x * Math.PI) );// output the Area
System.out.printf("Circumference is %f\n", (2 * x * Math.PI) );// output the circumference
System.out.printf("Diameter is %f\n", (2 * x) );// output the diameter using printf
}//end main
}//end class Circle
•
•
Join Date: Jun 2009
Posts: 830
Reputation:
Solved Threads: 94
Practically a Posting Shark
Post your entire code! Errors can be misleading without seeing everything in context!
For example if x is an integer or a double it can cause a problem with that printf. The fact that it was multiplied with a float (PI) would make the result a float.
For example if x is an integer or a double it can cause a problem with that printf. The fact that it was multiplied with a float (PI) would make the result a float.
Last edited by wildgoose; Jul 7th, 2009 at 1:58 am. Reason: addendum
•
•
Join Date: Apr 2008
Posts: 971
Reputation:
Solved Threads: 146
Posting Shark
Because x is assigned from an input.nextInt(), I assume it's declared as int, so:
%f requires a floating point value, but 2*x is an integer value. Change the format to %d when you print the diameter, OR change the calculation to 2.0*x so the result is floating point.
%f requires a floating point value, but 2*x is an integer value. Change the format to %d when you print the diameter, OR change the calculation to 2.0*x so the result is floating point.
Last edited by JamesCherrill; Jul 7th, 2009 at 1:28 pm.
•
•
•
•
Originally Posted by JamesCherrill
Because x is assigned from an input.nextInt(), I assume it's declared as int, so:
%f requires a floating point value, but 2*x is an integer value. Change the format to %d when you print the diameter, OR change the calculation to 2.0*x so the result is floating point.
 |
Similar Threads
- Get form to send email (ASP)
- Having trouble understanding how header files work. (C++)
- Bay Area Rental Housing Web Startup (Web Development Job Offers)
- Software engineer for start up in Bay area (Software Development Job Offers)
- area/volume (C)
- trouble understanding widget commands (Python)
- need help with programing with fstream to find area of triangle (C++)
- Connection Problems (Networking Hardware Configuration)
Other Threads in the Java Forum
- Previous Thread: How to get or calculate coordinates?
- Next Thread: What is the function of "-d ." command?
| Thread Tools | Search this Thread |
You need to join our community in order to build your list of favorite forums. You can visit the forum index for a listing of all forums.
Related Forum Features
Latest Java Posts
- Today's Posts
- Unanswered Threads
911 addball addressbook android api append applet application apps array arrays automation binary bluetooth businessintelligence button card class client code collision component crashcourse css csv database eclipse ee error fractal free ftp game gis givemetehcodez graphics gui html ide image integer integration j2me japplet java javaarraylist javadoc javafx javaprojects jni jpanel julia jvm linked linux list loan machine map method methods migrate mobile netbeans objects oriented output phone physics printf problem program programming project projects radio recursion replaydirector reporting researchinmotion rotatetext scanner se server service set sms software sort sql string swing test textfield threads tree trolltech ubuntu utility windows
