摘要:
向下转型一定是new子类的对象,再转型;不能new父类的对象 Person p = new Man(); Man m = (Man)p; integer i = new integer(1); integer j = new integer(1); i == j;//false integer m 阅读全文
摘要:
class test { public static void main(String[] args) { char letter[] = {'a','l'}; int num[] = new int[26]; for(int i = 0;i < letter.length;i++){ num[le 阅读全文