HashCode() is explicitly used in methods where hash functions are used, like hashTable() etc. One should always override hashCode() when overriding equals(). Unexpected behaviour will occur if you don't do so. HashCode() should have the same value whenever equals() returns true. Java中的集...
import java.util.*; public class TestMark_to_win { public static void main(String args[]) { HashSet h = new HashSet(); h.add("1"); h.add("2"); h.add("3"); h.add("4"); System.out.println(h); } }
HashCode() is explicitly used in methods where hash functions are used, like hashTable() etc. One should always override hashCode() when overriding equals(). Unexpected behaviour will occur if you don't do so. HashCode() should have the same value whenever equals() returns true. Java中的集...
For example, to add items to it, use the add() method:Example // Import the HashSet class import java.util.HashSet; public class Main { public static void main(String[] args) { HashSet<String> cars = new HashSet<String>(); cars.add("Volvo"); cars.add("BMW"); cars.add("Ford...
importjava.util.HashSet;importjava.util.Iterator;publicclasst6{publicstaticvoidmain(String[]args){// TODO Auto-generated method stub//创建HashSet集合HashSet hs=newHashSet();//向hs集合添加元素hs.add("aa");hs.add("bb");hs.add("cc");hs.add("dd");//获取Iterator对象Iterator it=hs.iterat...
Creates alate-bindingandfail-fastSpliteratorover the elements in this set. Methods inherited from class java.util.AbstractSet equals,hashCode,removeAll Methods inherited from class java.util.AbstractCollection addAll,containsAll,retainAll,toArray,toArray,toString ...
implements Set<E>, Cloneable, java.io.Serializable { static final long serialVersionUID = -5024744406713321676L; // 底层使用HashMap来保存HashSet中所有元素。 private transient HashMap<E,Object> map; // 定义一个虚拟的Object对象作为HashMap的value,将此对象定义为static final。
AddFirst(Object) Attributes RegisterAttribute Remarks To be added If this set already contains the element, it is relocated if necessary so that it is first in encounter order. Added in 21. Java documentation forjava.util.LinkedHashSet.addFirst(E). ...
strs.add(s5); strs.add(s6); System.out.println(strs.size());for(String str:strs){ System.out.println(str); } } } 结果: 3102327948732798884567 TreeSet排序的问题: 默认排序: importjava.util.Iterator;importjava.util.Set;importjava.util.TreeSet;importjava.util.Comparator;publicclassMain {/...
Firstly we’ll look at theConcurrentHashMapclass that exposed the staticnewKeySet()method. Basically, this method returns an instance that respects thejava.util.Setinterface and allows the usage of standard methods likeadd(), contains(),etc. ...