can't import any java libraries...

[rudeboymcc]

Hi. Just installed the java SDK on my vista machine but i'm having trouble getting any library functions to work.

for example i'm trying to use square root (sqrt) which is in java.lang.Math. I've put this at the top:

import java.lang.Math;

but when i try to compile I get "cannot find symbol" and points to where I've used sqrt.

i have the same trouble when tryin to use words for colours (i..e black rather than 0,0,0 RGB).

anyone have any ideas?

 

[RobH]

Well all of the methods in java.lang.Math are static (you don't need to construct an object to use them) so you need to make a static call to the method. For example:

import java.lang.Math;

[I]<snip>[/I]

double x = 100;
double result = Math.sqrt(x);
System.out.println(result);

//Output:
10.0

Likewise with the colours, you need to have a static reference to the field in the java.awt.Color class. For example:

import java.awt.Color;

[I]<snip>[/I]

Color c = Color.BLACK

 

[rudeboymcc]

THANKS! can't belive it was that simple, was usiong the C++ method of just calling sqrt.


and cheers for the very fast answer