問(wèn)題描述

Collection c2 =new ArrayList();Student s= new Student();c2.add(s);c2.add('我');Iterator it = c2.iterator();while (it.hasNext()) { it.next(); Object object = (Object) it.next(); System.out.println(object);}輸出結(jié)果為“我”，并沒(méi)有s對(duì)象啊？

問(wèn)題解答

while (it.hasNext()) { it.next(); //第一個(gè)對(duì)象 Student Object object = (Object) it.next(); //第二個(gè)對(duì)象 String System.out.println(object);}

while循環(huán)里一次next了兩次

沒(méi)有定義str方法的類不能println出想要的東西來(lái)。

it.next()循環(huán)了兩次

it.next()循環(huán)了倆次哦！