String的API中解释: Returns a hash code for this string. The hash code for a String object is computed as s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1] 返回值int为位置,这里 s[i] 是字符串的第 i 个字符,n 是字符串的长度,^ 表示求幂。(空字符串的哈希码为 0。) 1. 2...
String的API中解释: Returns a hash code for this string. The hash code for aStringobject is computed as s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1] 返回值int为位置,这里 s[i] 是字符串的第 i 个字符,n 是字符串的长度,^ 表示求幂。(空字符串的哈希码为 0。) hashcode()...
*@returnthe number of elements in this set (its cardinality)*/publicintsize() {returnmap.size(); }/*** Returns {@codetrue} if this set contains no elements. * * 判断set是否不包含任何元素,是则返回true *@return{@codetrue} if this set contains no elements*/publicbooleanisEmpty() {retu...
publicclassJavaProGuideTest{publicstaticvoidmain(String[]args){TreeSetset=newTreeSet(newComparator()...
java中HashSet有什么用,举例说明 2.1 HashSet的用法 对象也必须定义hashCode(),比如下面例子2.1.1中的String类中就定义了hashCode方法。 h.add("1"); 但随着Set的增大,它的性能不会大打折扣。这是由Hash的低层结构决定的。HashSet不保证输出的顺序。
* e2)} must not throw a {@code ClassCastException} for any elements * {@code e1} and {@code e2} in the set. If the user attempts to add * an element to the set that violates this constraint, the * {@code add} call will throw a {@code ClassCastException}. ...
java version "1.7.0-internal-zing_99.99.99.99.dev" Zing Runtime Environment for Java ...
HashSet是一个不允许存储重复元素的集合,它的实现比较简单,只要理解了HashMap,HashSet就水到渠成了。 成员变量 首先了解下HashSet的成员变量: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 privatetransient HashMap<E,Object>map;// Dummy value to associate with an Object in the backing Mapprivatesta...
Returns a hash code value for the object. (Inherited from Object) Iterator() Returns an iterator over the elements in this set. JavaFinalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Ob...
* * @return a {@code Spliterator} over the elements in this set * @since 1.8 */ //为了并行遍历数据源中的元素而设计的迭代器 public Spliterator<E> spliterator() { return new HashMap.KeySpliterator<E,Object>(map, 0, -1, 0, 0); } }©...