Java Programming Quiz

Which of the following is not a valid Java identifier?

• _main

• $value

• 9data

• data_9

What is the result of the following? System.out.println(10 + 20 + "30" + 40 + 50);

• 30304050

• 30204050

• 303050

• 303040

Which of the following is a correct way to assign a float value?

• float f = 10.2;

• float f = 10.2f;

• float f = (float)10.2;

• Both B and C

What will this print? int x = 5; System.out.println(x++ + ++x);

• 11

• 12

• 13

• 10

What is the output? int x = 0; if (x == 0) x = 1; if (x == 1) x = 2; else x = 3; System.out.println(x);

• 2

• 3

• 1

• Compile-time error

What will be the result of this code? int arr[] = new int[5]; System.out.println(arr[0]);

• 0

• null

• Garbage value

• Error

Which of the following returns true? String s1 = "Java"; String s2 = new String("Java");

• s1 == s2

• s1.equals(s2)

• Both

• None

Which method is called? class A { void show() { System.out.println("A"); } } class B extends A { void show() { System.out.println("B"); } } public class Test { public static void main(String[] args) { A obj = new B(); obj.show(); } }

• A

• B

• Error

• Depends on JVM

Can an interface have a constructor in Java?

• Yes

• No

What happens? try { int x = 5 / 0; } catch (Exception e) { System.out.println("Exception"); }

• Compile-time error

• Runtime exception handled

• JVM crash