Java static methods

When using Java, you will find that some objects need new, others do not, such as the math class

int c = math.abs (2);

If you look at the source code will be generally found that the properties and methods are static:

     Public Static double sin (double  a) {        return//  default impl. Delegates to Strictmath    }    publicstaticdouble ASIN (double  a) {        return//  default impl. Delegates to Strictmath    }

If the instance variable and the instance method belong to an object,

So: static variables, and static methods belong to all objects, so do not use a new variable can be used.

In this case, the general use of Java in some of the tools of the room when used more.

Java static methods