203 *
204 * @return the number of elements in this set (its cardinality)
205 */
206 public int size() {
207 return m.size();
208 }
209
210 /**
211 * Returns {@code true} if this set contains no elements.
212 *
213 * @return {@code true} if this set contains no elements
214 */
215 public boolean isEmpty() {
216 return m.isEmpty();
217 }
218
219 /**
220 * Returns {@code true} if this set contains the specified element.
221 * More formally, returns {@code true} if and only if this set
222 * contains an element {@code e} such that
223 * <tt>(o==null ? e==null : o.equals(e))</tt>.
224 *
225 * @param o object to be checked for containment in this set
226 * @return {@code true} if this set contains the specified element
227 * @throws ClassCastException if the specified object cannot be compared
228 * with the elements currently in the set
229 * @throws NullPointerException if the specified element is null
230 * and this set uses natural ordering, or its comparator
231 * does not permit null elements
232 */
233 public boolean contains(Object o) {
234 return m.containsKey(o);
235 }
236
237 /**
238 * Adds the specified element to this set if it is not already present.
239 * More formally, adds the specified element {@code e} to this set if
240 * the set contains no element {@code e2} such that
241 * <tt>(e==null ? e2==null : e.equals(e2))</tt>.
242 * If this set already contains the element, the call leaves the set
243 * unchanged and returns {@code false}.
244 *
245 * @param e element to be added to this set
246 * @return {@code true} if this set did not already contain the specified
247 * element
248 * @throws ClassCastException if the specified object cannot be compared
249 * with the elements currently in this set
250 * @throws NullPointerException if the specified element is null
251 * and this set uses natural ordering, or its comparator
252 * does not permit null elements
253 */
254 public boolean add(E e) {
255 return m.put(e, PRESENT)==null;
256 }
257
258 /**
259 * Removes the specified element from this set if it is present.
260 * More formally, removes an element {@code e} such that
261 * <tt>(o==null ? e==null : o.equals(e))</tt>,
262 * if this set contains such an element. Returns {@code true} if
263 * this set contained the element (or equivalently, if this set
264 * changed as a result of the call). (This set will not contain the
265 * element once the call returns.)
266 *
267 * @param o object to be removed from this set, if present
268 * @return {@code true} if this set contained the specified element
269 * @throws ClassCastException if the specified object cannot be compared
270 * with the elements currently in this set
271 * @throws NullPointerException if the specified element is null
272 * and this set uses natural ordering, or its comparator
273 * does not permit null elements
274 */
275 public boolean remove(Object o) {
276 return m.remove(o)==PRESENT;
277 }
278
279 /**
280 * Removes all of the elements from this set.
281 * The set will be empty after this call returns.
|
203 *
204 * @return the number of elements in this set (its cardinality)
205 */
206 public int size() {
207 return m.size();
208 }
209
210 /**
211 * Returns {@code true} if this set contains no elements.
212 *
213 * @return {@code true} if this set contains no elements
214 */
215 public boolean isEmpty() {
216 return m.isEmpty();
217 }
218
219 /**
220 * Returns {@code true} if this set contains the specified element.
221 * More formally, returns {@code true} if and only if this set
222 * contains an element {@code e} such that
223 * <code>(o==null ? e==null : o.equals(e))</code>.
224 *
225 * @param o object to be checked for containment in this set
226 * @return {@code true} if this set contains the specified element
227 * @throws ClassCastException if the specified object cannot be compared
228 * with the elements currently in the set
229 * @throws NullPointerException if the specified element is null
230 * and this set uses natural ordering, or its comparator
231 * does not permit null elements
232 */
233 public boolean contains(Object o) {
234 return m.containsKey(o);
235 }
236
237 /**
238 * Adds the specified element to this set if it is not already present.
239 * More formally, adds the specified element {@code e} to this set if
240 * the set contains no element {@code e2} such that
241 * <code>(e==null ? e2==null : e.equals(e2))</code>.
242 * If this set already contains the element, the call leaves the set
243 * unchanged and returns {@code false}.
244 *
245 * @param e element to be added to this set
246 * @return {@code true} if this set did not already contain the specified
247 * element
248 * @throws ClassCastException if the specified object cannot be compared
249 * with the elements currently in this set
250 * @throws NullPointerException if the specified element is null
251 * and this set uses natural ordering, or its comparator
252 * does not permit null elements
253 */
254 public boolean add(E e) {
255 return m.put(e, PRESENT)==null;
256 }
257
258 /**
259 * Removes the specified element from this set if it is present.
260 * More formally, removes an element {@code e} such that
261 * <code>(o==null ? e==null : o.equals(e))</code>,
262 * if this set contains such an element. Returns {@code true} if
263 * this set contained the element (or equivalently, if this set
264 * changed as a result of the call). (This set will not contain the
265 * element once the call returns.)
266 *
267 * @param o object to be removed from this set, if present
268 * @return {@code true} if this set contained the specified element
269 * @throws ClassCastException if the specified object cannot be compared
270 * with the elements currently in this set
271 * @throws NullPointerException if the specified element is null
272 * and this set uses natural ordering, or its comparator
273 * does not permit null elements
274 */
275 public boolean remove(Object o) {
276 return m.remove(o)==PRESENT;
277 }
278
279 /**
280 * Removes all of the elements from this set.
281 * The set will be empty after this call returns.
|