set系列集合,是无序的,并且无索引,还不允许数据重复




package com.jdL.day22classwork;
import java.util.Comparator;
import java.util.Iterator;
import java.util.TreeSet;
import java.util.function.Consumer;
public class TreeSetTest1 {
public static void main(String[] args) {
//创建Treeset对象
TreeSet<Integer> ts=new TreeSet<>();
ts.add(3);
ts.add(5);
ts.add(1);
ts.add(4);
ts.add(2);
System.out.println(ts);
//遍历
//1、迭代器
Iterator<Integer> iterator = ts.iterator();
while(iterator.hasNext()){
Integer i = iterator.next();
System.out.print(i);
}
//增强for
for(Integer x:ts){
System.out.print(x);}
System.out.println("--------------");
//lamdba表达式
ts.forEach(i->System.out.print(i)
);
}
}




