Java Functions

Question 1

Output of following Java program?

C

class Main {
    public static void main(String args[]) {   
             System.out.println(fun());
    } 
 
    int fun()
    {
      return 20;
    }
}

• 20
• compiler error
• 0
• garbage value

Question 2

C

public class Main { 
    public static void main(String args[]) { 
       String x = null; 
       giveMeAString(x); 
       System.out.println(x); 
    } 
    static void giveMeAString(String y) 
    { 
       y = \"GeeksQuiz\"; 
    } 
}

• GeeksQuiz
• null
• Compiler Error
• Exception

Question 3

Java

class intWrap {
   int x;
} 
public class Main { 
    public static void main(String[] args) {
       intWrap i = new intWrap();
       i.x = 10;
       intWrap j = new intWrap();
       j.x = 20;
       swap(i, j);
       System.out.println(\"i.x = \" + i.x + \", j.x = \" + j.x);
    } 
    public static void swap(intWrap i, intWrap j) {
       int temp = i.x;
       i.x = j.x;
       j.x = temp;
    }
}

• i.x = 20, j.x = 10
• i.x = 10, j.x = 20
• i.x = 10, j.x = 10
• i.x = 20, j.x = 20

Question 4

In Java, can we make functions inline like C++?

• Yes
• No

Question 5

Predict the output?

Java

class Main {
    public static void main(String args[]) {   
             System.out.println(fun());
    }   
    static int fun(int x = 0)
    {
      return x;
    }
}

• 0
• Garbage Value
• Compiler Error
• Runtime Error

Question 6

Predict the output of the following program.

Java

class Test
{
    public static void main(String[] args)
    {
        StringBuffer a = new StringBuffer(\"geeks\");
        StringBuffer b = new StringBuffer(\"forgeeks\");
        a.delete(1,3);
        a.append(b);
        System.out.println(a);
    }
}

• gsforgeeks
• gksforgeeks
• geksforgeeks
• Compilation error

Question 7

Predict the output of the following program.

Java

 class Test
{

    public static void main(String[] args)
    {
        String obj1 = new String(\"geeks\");
        String obj2 = new String(\"geeks\");

        if(obj1.hashCode() == obj2.hashCode())
            System.out.println(\"hashCode of object1 is equal to object2\");

        if(obj1 == obj2)
            System.out.println(\"memory address of object1 is same as object2\");

        if(obj1.equals(obj2))
            System.out.println(\"value of object1 is equal to object2\");
    }
}

• hashCode of object1 is equal to object2
  value of object1 is equal to object2

• hashCode of object1 is equal to object2
  memory address of object1 is same as object2
  value of object1 is equal to object2

• memory address of object1 is same as object2
  value of object1 is equal to object2

Question 8

Predict the output of the following program.

Java

 class Test implements Cloneable
{
    int a;

    Test cloning()
    {
        try
        {
            return (Test) super.clone();
        }
        catch(CloneNotSupportedException e)
        {
            System.out.println(\"CloneNotSupportedException is caught\");
            return this;
        }
    }
}

class demo
{

    public static void main(String args[])
    {
        Test obj1 = new Test();
        Test obj2;
        obj1.a = 10;
        obj2 = obj1.cloning();
        obj2.a = 20;

        System.out.println(\"obj1.a = \" + obj1.a);
        System.out.println(\"obj2.a = \" + obj2.a);
    }
}

• obj1.a = 10
  obj2.a = 20

• obj1.a = 20
  obj2.a = 20

• obj1.a = 10
  obj2.a = 10

Question 9

Predict the output of the following program.

Java

class Test
{
    public static void main(String[] args)
    {
        String str = \"geeks\";
        str.toUpperCase();
        str += \"forgeeks\";
        String string = str.substring(2,13);
        string = string + str.charAt(4);;
        System.out.println(string);
    }
}

• eksforgeekss
• eksforgeeks
• EKSforgeekss
• EKSforgeeks

Question 10

Given the array of integers ‘array’ shown below : 13, 7, 27, 2, 18, 33, 9, 11, 22, 8. What is the output of the following JAVA statements ?

int [ ] p = new int [10];
int [ ] q = new int [10];
for (int k = 0; k < 10; k ++)
p[k] = array [k];
q = p;
p[4] = 20;
System.out.println(array [4] + “ : ” + q[4]);

• 20 : 20
• 18 : 18
• 18 : 20
• 20 : 18