集合Collection和List（二）

一.集合去除重复

ArrayList list=new ArrayList();
list.add("hello")
list.add("nihao");
list.add("hello");
ArrayList newArraylist=new ArrayLisy();
Iterator it=list.iterator();
while(it.hasNext()){
Stirng s=(Stirng) it.next()
if(!newArraylist.contains(s)){
 newArraylist.add(s);
for(int i=0;i