What will be the output of the program? public class Test { public static void main (String args[]) { String str = NULL; System.out.println(str); } }

Q: What will be the output of the program? public class Test { public static void main (String args[]) { String str = NULL; System.out.println(str); } }

Option B is correct because to set the value of a String variable to null you must use "null" and not "NULL".

NULL
Compile Error
Code runs but no output
Runtime Exception

Correct Answer: Compile Error

Explanation:

Option B is correct because to set the value of a String variable to null you must use "null" and not "NULL".

More Questions from Objects and Collections

What will be the output of the program? public class Test { public static void main (String[] args) { String foo = args[1]; String bar = args[2]; String baz = args[3]; System.out.println("baz = " + baz); /* Line 8 */ } } And the command line invocation: > java Test red green blue
What will be the output of the program? public static void main(String[] args) { Object obj = new Object() { public int hashCode() { return 42; } }; System.out.println(obj.hashCode()); }
Which two statements are true about comparing two instances of the same class, given that the equals() and hashCode() methods have been properly overridden? If the equals() method returns true, the hashCode() comparison == must return true. If the equals() method returns false, the hashCode() comparison != must return true. If the hashCode() comparison == returns true, the equals() method must return true. If the hashCode() comparison == returns true, the equals() method might return true.
Assuming that the equals() and hashCode() methods are properly implemented, if the output is "x = 1111", which of the following statements will always be true? x = 0; if (x1.hashCode() != x2.hashCode() ) x = x + 1; if (x3.equals(x4) ) x = x + 10; if (!x5.equals(x6) ) x = x + 100; if (x7.hashCode() == x8.hashCode() ) x = x + 1000; System.out.println("x = " + x);
What two statements are true about properly overridden hashCode() and equals() methods? hashCode() doesn't have to be overridden if equals() is. equals() doesn't have to be overridden if hashCode() is. hashCode() can always return the same value, regardless of the object that invoked it. equals() can be true even if it's comparing different objects.
Which statement is true for the class java.util.HashSet?
Which of the following are true statements? The Iterator interface declares only three methods: hasNext, next and remove. The ListIterator interface extends both the List and Iterator interfaces. The ListIterator interface provides forward and backward iteration capabilities. The ListIterator interface provides the ability to modify the List during iteration. The ListIterator interface provides the ability to determine its position in the List.
Which statement is true for the class java.util.ArrayList?
Which of the following statements about the hashcode() method are incorrect? The value returned by hashcode() is used in some collection classes to help locate objects. The hashcode() method is required to return a positive int value. The hashcode() method in the String class is the one inherited from Object. Two new empty String objects will produce identical hashcodes.
Which statement is true? class Test1 { public int value; public int hashCode() { return 42; } } class Test2 { public int value; public int hashcode() { return (int)(value^5); } }

Discussion & Comments

No comments yet. Be the first to comment!