Volume of a Cylinder. The result is off by one decimal point.

[halciu]

I need to write a program to compute the Volume of a Cylinder by Repeated Addition.

This is what I got so far:

double radius, hight, volume, pi = 3.1416, x, y, z;

Scanner keyboard = new Scanner (System.in);

System.out.println("Enter the radius: ");
radius = keyboard.nextDouble ();

System.out.println("Enter the hight: ");
hight = keyboard.nextDouble ();

x=0;
for (int i=0; i<radius; i++)
x+=radius;

y=0;
for (int j=0 ; j<hight;j++)
y+= hight;

z=0;
for (int k=0; k<y ; k++)
z+=pi;

volume = z;
System.out.println("The volume is: " + volume);

When I run the program The result is off by one decimal point.

Ex: radius = 10, hight = 10
Result will come back as 314.16 when it should be 3141.6

I'm stuck and do not know how to solve this issue.

[Chervil]

Doesn't look like C or C++ :)

But anyway the algorithm looks wrong. What use is made of the value of variable x ?

Also, since the loops can iterate only a whole number of times, several of the variables should be of integer type.

[ShiftLeft]

This just so happened to turn out this way because you used two equal values being 10. If you would have used lets say 18 & 34, then it would probably have been much more evident.

In any case;

    z = 0;
    for ( int k = 0; k < y; k++ )
        z += pi;

y is not including x and that is why your off by one decimal.

Enclosing code with code tags

would have been easier to point out error by line number.