[SOLVED] basic java help getting error in netbeans and at commandline

[aszxcv]

public class math {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
int x = (int) Math.PI * 20.0;
System.out.println(x);

}

}





found : double
required: int
int x = (int) Math.PI * 20.0;
1 error
BUILD FAILED (total time: 0 seconds)



the code is suppose to round math pi to 3 and then multiple by 20 and produce the answer 60. but i keep getting the error above when i try to build this project:confused:

[achelis]

20.0 is explicitly a double.

That means you're casting the Math.PI constant to an int then multiplying it by a double which results in a double.

Changing x to a double would give you the result you're after as a double.

Changing 20.0 to 20 (which is an int) would give the result you're after as an int.

Hope that made sense, otherwise feel free to ask again :)

Edit:
Quick note on literals in Java:


Literal Type
10 integer
10l long
10f float
10.0 double
10d double

[aszxcv]

gotcha thanks for explanation .

[meanburrito920]

It is often useful to just throw a pair of parenthesis around the entire expression that is being cast, which takes care of any ambiguities in order of operations.
So for example the line



int x = (int) Math.PI * 20.0;


would become



int x = (int) ( Math.PI * 20.0 );


and would work just fine.