Question

I’m learning Java and I just wonder why public and private is used when a method or members is static? When static is used they are class methods and class members and could be used from other classes without creating an object, so is public and private necessary? Some help is preciated to understand. Sorry if this question is too simple for some.

Answer 1

The accessibility of a field or method is orthogonal to the fact that it’s static or not.

You could have a static method accessible from the outside, and a static method that must only be used from inside the class itself (by other static or non-static methods). The same goes for fields.

For example:

// not visible from the outside
private static final long MILLISECONDS_IN_A_MINUTE = 1000L * 60 * 60;

public static Date addMinutes(Date d, int amount) {
    return addMillis(d, MILLISECONDS_IN_A_MINUTE * amount);
}

// not visible from the outside
private static Date addMillis(Date d, long amount) {
    return new Date(d.getTime() + amount);
}