Restrictions On Generics(Computer Science > Java Program ) Questions and Answers
Question 1.
import java.util.*;
public class genericstack {
Stack stk = new Stack ();
public void push(E obj) {
stk.push(obj);
}
public E pop() {
E obj = stk.pop();
return obj;
}
}
class Output {
public static void main(String args[]) {
genericstack gs = new genericstack();
gs.push(36);
System.out.println(gs.pop());
}
}
What is the output of this program?
import java.util.*;
public class genericstack {
Stack stk = new Stack ();
public void push(E obj) {
stk.push(obj);
}
public E pop() {
E obj = stk.pop();
return obj;
}
}
class Output {
public static void main(String args[]) {
genericstack gs = new genericstack();
gs.push(36);
System.out.println(gs.pop());
}
}
Explanation:-
Answer: Option D. -> Compilation Errorgenericstack's object gs is defined to contain a string parameter but we are
sending an integer parameter, which results in compilation error.
Output:
$ javac Output.java
$ java Output
Hello
Question 4.
import java.util.*;
public class genericstack {
Stack stk = new Stack ();
public void push(E obj) {
stk.push(obj);
}
public E pop() {
E obj = stk.pop();
return obj;
}
}
class Output {
public static void main(String args[]) {
genericstack gs = new genericstack();
gs.push("Hello");
System.out.print(gs.pop() + " ");
genericstack gs = new genericstack();
gs.push(36);
System.out.println(gs.pop());
}
}
What is the output of this program?
import java.util.*;
public class genericstack {
Stack stk = new Stack ();
public void push(E obj) {
stk.push(obj);
}
public E pop() {
E obj = stk.pop();
return obj;
}
}
class Output {
public static void main(String args[]) {
genericstack gs = new genericstack();
gs.push("Hello");
System.out.print(gs.pop() + " ");
genericstack gs = new genericstack();
gs.push(36);
System.out.println(gs.pop());
}
}
Explanation:-
Answer: Option D. -> Hello 36None.
Output:
$ javac Output.java
$ java Output
Hello 36