datalab2

DataLabs/lab2/BagInterface.java

@@ -0,0 +1,48 @@
+/**
+   An interface that describes the operations of a bag of objects.
+   @author Frank M. Carrano
+   @version 4.0
+*/
+public interface BagInterface<T>
+{
+	/** Gets the current number of entries in this bag.
+		 @return  The integer number of entries currently in the bag. */
+	public int getCurrentSize();
+	
+	/** Sees whether this bag is empty.
+		 @return  True if the bag is empty, or false if not. */
+	public boolean isEmpty();
+	
+	/** Adds a new entry to this bag.
+	    @param newEntry  The object to be added as a new entry.
+	    @return  True if the addition is successful, or false if not. */
+	public boolean add(T newEntry);
+
+	/** Removes one unspecified entry from this bag, if possible.
+       @return  Either the removed entry, if the removal.
+                was successful, or null. */
+	public T remove();
+   
+	/** Removes one occurrence of a given entry from this bag.
+       @param anEntry  The entry to be removed.
+       @return  True if the removal was successful, or false if not. */
+   public boolean remove(T anEntry);
+	
+	/** Removes all entries from this bag. */
+	public void clear();
+	
+	/** Counts the number of times a given entry appears in this bag.
+		 @param anEntry  The entry to be counted.
+		 @return  The number of times anEntry appears in the bag. */
+	public int getFrequencyOf(T anEntry);
+	
+	/** Tests whether this bag contains a given entry.
+		 @param anEntry  The entry to locate.
+		 @return  True if the bag contains anEntry, or false if not. */
+	public boolean contains(T anEntry);
+   
+	/** Retrieves all entries that are in this bag.
+		 @return  A newly allocated array of all the entries in the bag.
+                Note: If the bag is empty, the returned array is empty. */
+	public T[] toArray();
+} // end BagInterface