Q. Which collection class allows you to grow or shrink its size and provides indexed access to its elements, but whose methods are not synchronized?

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Q. You need to store elements in a collection that guarantees that no duplicates are stored and all elements can be accessed in natural order. Which interface provides that capability?

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Q. Which interface does java.util.Hashtable implement?

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Q. Which interface provides the capability to store objects using a key-value pair?

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Q. Which collection class allows you to associate its elements with key values, and allows you to retrieve objects in FIFO (first-in, first-out) sequence?

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Q. Which collection class allows you to access its elements by associating a key with an element's value, and provides synchronization?

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Q. Which is valid declaration of a float?

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Q. Which of the following are true statements?

1. The Iterator interface declares only three methods: hasNext, next and remove.
2. The ListIterator interface extends both the List and Iterator interfaces.
3. The ListIterator interface provides forward and backward iteration capabilities.
4. The ListIterator interface provides the ability to modify the List during iteration.
5.The ListIterator interface provides the ability to determine its position in the List.

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Q. Which statement is true for the class java.util.ArrayList?

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Q. Which statement is true for the class java.util.HashSet?

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Q. Which of the following statements about the hashcode() method are incorrect?

1. The value returned by hashcode() is used in some collection classes to help locate objects.
2. The hashcode() method is required to return a positive int value.
3. The hashcode() method in the String class is the one inherited from Object.
4. Two new empty String objects will produce identical hashcodes.

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Q. What two statements are true about properly overridden hashCode() and equals() methods?

1. hashCode() doesn't have to be overridden if equals() is.
2. equals() doesn't have to be overridden if hashCode() is.
3. hashCode() can always return the same value, regardless of the object that invoked it.
4. equals() can be true even if it's comparing different objects.

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Q. Which two statements are true about comparing two instances of the same class, given that the equals() and hashCode() methods have been properly overridden?

1. If the equals() method returns true, the hashCode() comparison == must return true.
2. If the equals() method returns false, the hashCode() comparison != must return true.
3. If the hashCode() comparison == returns true, the equals() method must return true.
4.If the hashCode() comparison == returns true, the equals() method might return true.

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Q. Which of the following is smallest integer data type ?

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Q. Which of the following is not a primitive data type ?

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Q. Integer Data type does not include following primitive data type ____________.

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Q. Which of the following data types comes under floating data types ?

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Q. Which of the following values, cannot be stored using Character data type?

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Q. Range of Byte Data Type is ____________.

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Q. What is size of integer in Java Programming?

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