AP® Computer Science A glossary

Class variable

Also called: static variable

Course: AP® Computer Science A Shows up in: Unit 3: Class Creation

An attribute declared with the keyword static that belongs to the class, so all objects of the class share a single copy.

Appears in the course and exam description (CED): 3.1.A.33.7.B.13.7.B.2

Class variables are often counters or constants. Class methods and instance methods can both use them. A public class variable is reached from other classes with the class name and the dot operator.

public class Ticket
{
    private static int sold = 0;   // one copy for the class

    public Ticket()
    {
        sold++;
    }

    public static void main(String[] args)
    {
        new Ticket();
        new Ticket();
        System.out.println(Ticket.sold);
    }
}

Output:

2

Related terms

• Instance variable
• final
• Class