遍歷Hashtable中的key和value的幾種方法
阿新 • • 發佈:2019-01-04
package coreJava; import java.util.Enumeration; import java.util.Hashtable; import java.util.Iterator; /* * 處理原則:先取出key,再利用key獲取value */ public class HashtableDemo { public static void main(String[] args) { Hashtable<String,String> ht = new Hashtable<String,String>(); for(int i = 0;i<10;i++){ ht.put("key"+i, "value"+i); } //利用迴圈遍歷出key和value for(Iterator<String> itr = ht.keySet().iterator();itr.hasNext();){ String key = (String)itr.next(); String value = (String)ht.get(key); System.out.println(key+" (for) "+value); } //利用迴圈遍歷出key和value Iterator<String> itr = ht.keySet().iterator(); while (itr.hasNext()){ String str = (String)itr.next(); System.out.println(str+" (while) "+ht.get(str)); } //利用列舉獲取value Enumeration<String> e = ht.elements(); while(e.hasMoreElements()){ System.out.println(e.nextElement()); } //利用列舉獲取key:value對兒 Enumeration<String> e2 = ht.keys(); while(e2.hasMoreElements()){ String key = e2.nextElement(); System.out.println(key+" = "+ht.get(key)); } } }