Question

Consider the following interface:

interface Validate

{

boolean check(Object o);

}

Classes that implement Validate interface, check against specific conditions to evaluate the object O. For example, a class validateAge checks if a birth year indicated by the person’s age is over 18 years old or not. If v is a validateAge object, then v.check(2001) returns true, and v.check(2003) returns false.

Write the class validateAge, and recall casting from a type to another.

Answer 1

SOURCE CODE IN JAVA:

Validate.java

interface Validate

{

//abstract method to be defined in implementing class

boolean check(Object o);

}

ValidateAge.java

class ValidateAge implements Validate

{

//defining abstract method from Interface

//accepts an year and returns if age is 18 or above

public boolean check(Object o)

{

//checking if parameter is an Integer

if(!(o instanceof Integer))

return false;

//type casting to int

int year=(int)o;

//checking if age is 18 and above

if(2020-year>=18)

return true;

return false;

}

}

Main.java

class Main

{

public static void main(String[] args)

{

//testing the class

ValidateAge v=new ValidateAge();

System.out.println(v.check(2001));

System.out.println(v.check(2003));

}

}

OUTPUT:

true false