Question

java

Give an example of a class that contains at least one class variable and at least one class method. Explain why using a class variable and method rather than an instance variable and method would be the correct choice in the example you select.

Answer 1

ClassVarTest.java

public class ClassVarTest {

   public static int count = 0;
   public static void main(String[] args) {
       ClassVarTest c1 = new ClassVarTest();
       ClassVarTest c2 = new ClassVarTest();
       c1.increaseCount();
       System.out.println(count);
       c2.increaseCount();
       System.out.println(count);
   }
   public static void increaseCount(){
       count++;
   }
}

Output:

1

2

Here the class variable is "count" and class method is "increaseCount()"

Class variable and class methods are nothing but a static variables and static methods.

Class level ariable are accessed by all instance of the same class. It means same memory will be used for each of instance of a class. Some If once instance changes the value of classs variable that value is autmatically effects to the rest of all instances.

In our case, I am increasing count variable value in class method. When we use instance c1 that cout value is 1 and whn we use instance c2 count variable value is 2.