package Dec2016; public class Ques1207 { public static void main(String[] args) { new Test(); new Test(1); new Test("1"); System.out.println("实例数量为:"+Test.getNumOfInstances()); } } class Test{ private static int numOfInstances = 0; //…

package Dec2016; public class Ques1209 { public static void main(String[] args){ People g = new People("张三"); // 定义监护人 People p1 = new People("儿子1", g); People p2 = p1.clone(); // 儿子2的信息通过拷贝儿子1来的 p2.setName("儿子2"); p1.getGuar…

package Dec2016; import java.util.List; public class Ques1208 { public static void add(List<? extends Number> list){ // 加入一个元素 list.add(123); } } 今日问题: 请问主程序能否正常运行输出结果?(点击以下"[Java每日一题]20161208"查看20161207问题解析) 题目原发布于公众号.简书:[Java每日一题]2016120…

20170105问题解析请点击今日问题下方的"[Java每日一题]20170106"查看(问题解析在公众号首发,公众号ID:weknow619) package Jan2017; public class Ques0106 { public void method01(String... strings, int num){ } public void method02(String... strings, int... is){ } } 今日问题: 以上两个方法使用了变长参数,请问这…

20170104问题解析请点击今日问题下方的"[Java每日一题]20170105"查看(问题解析在公众号首发,公众号ID:weknow619) package Jan2017; import java.util.ArrayList; import java.util.List; public class Ques0105 { public static void main(String[] args) { List<String> list = new ArrayList…

20170103问题解析请点击今日问题下方的"[Java每日一题]20170104"查看(问题解析在公众号首发,公众号ID:weknow619) package Jan2017; import java.util.HashSet; import java.util.Set; public class Ques0104{ public static void main(String[] args){ Obj obj01 = new Obj("张三"); Obj obj…

20161230问题解析请点击今日问题下方的"[Java每日一题]20170103"查看(问题解析在公众号首发,公众号ID:weknow619) package Jan2017; public class Ques0103 { public static void main(String[] args){ System.out.println(delete("你好", "你").equals("好")); System.out…

// 20161229问题解析请点击今日问题下方的"[Java每日一题]20161230"查看(问题解析在公众号首发,公众号ID:weknow619)package Dec2016; public class Ques1230 { int array = {1, 2, 3}; // 1 int array[] = {1, 2, 3}; // 2 int[] array = {1, 2, 3}; // 3 int array[] = new int{1, 2, 3}; // 4 int…

package Dec2016; import java.util.ArrayList; import java.util.List; public class Ques1229 { public static void main(String[] args){ Student stu01 = new Student("001"); Student stu02 = new Student(null); List<Student> students = new ArrayLi…

package Dec2016; import java.util.ArrayList; import java.util.List; public class Ques1228 { public static void main(String[] arg){ Student stu01 = new Student("001"); Student stu02 = new Student("001 "); // stu02中001后面有个空格 List<Stud…