Set 锻炼

import java.util.HashSet;import java.util.Iterator;import java.util.Set;public class SetTest {public static void main(String[] args) {String [] a={"wang","zhang","li","wu","han"};//学生名单String [] b={"zhang,数学,88",//成绩名单     "zhang,语文,89",     "zhang,英语,78",     "wu,英语,88",     "wu,数学,88",     "tang,数学,88",     };//那些人什么都没考Set<String> sa=new HashSet<String>();for(int i=0;i<a.length;i++)sa.add(a[i]);Set<String> sb=new HashSet<String>();    for(int i=0;i<b.length;i++) sb.add(b[i].split(",")[0]);    sa.removeAll(sb);    //遍历set集合中的元素   Iterator<String> it=sa.iterator();   while(it.hasNext()){   System.out.println(it.next());   }   // System.out.println(sa);}}