java map统计学生名单_Java含自己的总结：集合，学生，遍历，ArrayList，Set,Map,泛型,班级，发牌—诗书画唱...
聲明一個ArrayList，存儲一條學生信息，內容為??1????張三???22????男，將信息進行遍歷出來
package list;
import java.util.ArrayList;
import java.util.Iterator;
public class student{
public static void main(String[] args) {
ArrayList jiHe = new ArrayList();
xueSheng xueSheng1 = new xueSheng(1,"張三",22,"男");
jiHe.add(xueSheng1);
for (int i = 0; i < jiHe.size(); i++) {
System.out.println(jiHe.get(i).toString());
}
}
}class xueSheng{
int bianhao;String name;int age;String sex;
public xueSheng(int bianhao, String name, int age, String sex) {
super();
this.bianhao = bianhao;
this.name = name;
this.age = age;
this.sex = sex;
}
@Override
public String toString() {
return "xueSheng [bianhao=" + bianhao + ", name=" + name + ", age="
+ age + ", sex=" + sex + "]";
}
}
聲明一個學生類，包含編號，名稱，年齡，和性別屬性，
實例化5名學生對象，將其保存在Set集合中，設置Set集合的泛型為SetXueSheng，遍歷該Set集合
package list;
import java.util.*;
import java.util.Map.Entry;
public class set {
public static void main(String[] args) {
HashSet jiHe=new HashSet();
SetXueSheng duiXiang1=new SetXueSheng(1,"詩書三連",18,"男");
SetXueSheng duiXiang2=new SetXueSheng(2,"畫唱點贊",19,"男");
SetXueSheng duiXiang3=new SetXueSheng(3,"詩書關注",20,"男");
SetXueSheng duiXiang4=new SetXueSheng(4,"畫唱收藏",21,"男");
SetXueSheng duiXiang5=new SetXueSheng(5,"詩書畫唱",22,"男");
jiHe.add(duiXiang1);
//第一個都要先放到集合中，之后才用Collections.addAll的方法。
//自己總結的語法：Collections.addAll(集合名,對象名1,對象名2,......)
Collections.addAll(jiHe,duiXiang2,duiXiang3,duiXiang4,duiXiang5);
for(SetXueSheng i:jiHe){
System.out.println(i);
}
}
}
class SetXueSheng{
public int bianhao;
public String name;
public int age;
public String sex;
public SetXueSheng(int bianhao, String name, int age, String sex) {
//super();可寫可不寫，因為沒寫父類，所以super();沒作用，也沒影響
this.bianhao = bianhao;
this.name = name;
this.age = age;
this.sex = sex;
}
@Override
public String toString() {
return "SetXueSheng [bianhao=" + bianhao
+ ", name=" + name + ", age="
+ age + ", sex=" + sex + "]";
}
}
聲明一個Map集合，設置泛型鍵為String，值為學生類，
將題2中的學生類保存在Map集合中，遍歷該Map集合
package list;
import java.util.*;
import java.util.Map.Entry;
public class map {
public static void main(String[] args) {
Map MapJiHe=
new HashMap();
//自己總結的語法：Map 集合名=
//new HashMap();
studentMapClass duiXiang1=new studentMapClass(1,"詩書畫唱",19,"男");
studentMapClass duiXiang2=new studentMapClass(2,"三連",20,"男");
studentMapClass duiXiang3=new studentMapClass(3,"關注",21,"男");
studentMapClass duiXiang4=new studentMapClass(4,"收藏",22,"男");
studentMapClass duiXiang5=new studentMapClass(5,"寶藏",23,"男");
//集合名.put(鍵(對應的數據類型的具體數據),值(對象名等));
MapJiHe.put("1",duiXiang1);MapJiHe.put("2",duiXiang2);
MapJiHe.put("3",duiXiang3);
MapJiHe.put("4",duiXiang4);MapJiHe.put("5",duiXiang5);
Iterator> dieDaiQi
=MapJiHe.entrySet().iterator();
//iterator
//[詞典]【計】迭代器，迭代程序;
//Iterator(迭代器)是一個接口，它的作用就是遍歷容器的所有元素。
//Iterator iter = list.iterator(); // 注意iterator，首字母小寫
while(dieDaiQi.hasNext()){
Entry rongQi
=dieDaiQi.next();
//entry英[?entri]
//美[?entri]
//n.進入(指行動); 進入(指權利等); 參與，加入(指權利、機會);
System.out.println("鍵為"+rongQi.getKey()
+"；值為"+rongQi.getValue());
}
}
}
class studentMapClass{
public int bianhao;
public String name;
public int age;
public String sex;
public studentMapClass(int bianhao,
String name, int age, String sex) {
//super();
this.bianhao = bianhao;
this.name = name;
this.age = age;
this.sex = sex;
}
@Override
public String toString() {
return "studentMapClass [bianhao=" + bianhao + ", name=" + name
+ ", age=" + age + ", sex=" + sex + "]";
}
}
聲明個map集合，設置鍵為班級名稱String，值為每個班級的所有學生信息ArrayList，用來存儲各個班級的學生信息,存儲3個班級的學生信息，并遍歷該map集合
package list;
import java.util.*;
import java.util.Map.Entry;
public class mapArrayList {
public static void main(String[] args) {
//可以用"//————————"來當分割線，分層，更容易看懂等
//自己的總結：先聲明一個HashMap集合
//再聲明3個ArrayList集合，最后用上
//HashMap集合名.put(鍵(這里聲明為String的內容),ArrayList集合名);
HashMap> HashMapJiHe
=new HashMap>();
//————————————————————————————————————————————————————————
ArrayList ArrayListJiHe1
=new ArrayList();//X班
studentMapArrayListClass duiXiang1=
new studentMapArrayListClass(1, "雙笙",18,"女");
studentMapArrayListClass duiXiang2=
new studentMapArrayListClass(2, "就是哈比",18,"女");
studentMapArrayListClass duiXiang3=
new studentMapArrayListClass(3, "諾鴿鴿",18,"女");
ArrayListJiHe1.add(duiXiang1);ArrayListJiHe1.add(duiXiang2);
ArrayListJiHe1.add(duiXiang3);
//——————————————————————————————————————————————————————————————————
ArrayList ArrayListJiHe2
=new ArrayList();//XX班
studentMapArrayListClass duiXiang11=
new studentMapArrayListClass(11, "封茗囧茵",18,"女");
studentMapArrayListClass duiXiang22=
new studentMapArrayListClass(22, "等人",18,"男");
studentMapArrayListClass duiXiang33=
new studentMapArrayListClass(33, "都會",18,"男");
ArrayListJiHe2.add(duiXiang11);
ArrayListJiHe2.add(duiXiang22);ArrayListJiHe2.add(duiXiang33);
//————————————————————————————————————————————————————————————————
ArrayList ArrayListJiHe3
=new ArrayList();//XXX班
studentMapArrayListClass duiXiang111=
new studentMapArrayListClass(111, "未來成為",18,"男");
studentMapArrayListClass duiXiang222=
new studentMapArrayListClass(222, "我詩書",18,"男");
studentMapArrayListClass duiXiang333=
new studentMapArrayListClass(333, "畫唱后宮",18,"男");
ArrayListJiHe3.add(duiXiang111);
ArrayListJiHe3.add(duiXiang222);
ArrayListJiHe3.add(duiXiang333);
//——————————————————————————————————————————————————
HashMapJiHe.put("X班",ArrayListJiHe1);HashMapJiHe.put("XX班",ArrayListJiHe2);
HashMapJiHe.put("XXX班",ArrayListJiHe3);
//————————————————————————————————————————————————
//聲明Iterator的自己總結的語法
//：Iterator>> Iterator名
//= HashMap集合名.entrySet().iterator();
//
//多找到,想到并且記錄等
//自己和別人容易理解,熟悉的,
//將其比作自己和別人容易理解,熟悉的。這樣可以更好的記憶，理解，
//認為懂了和獲得我們大多人定義的真正的懂了。很多東西等都是被定義的，本身并不存在
//所有的班級和學生等的內容會因為聲明了Iterator,而被裝到Iterator里面,
//
//Iterator等就像一個水杯,內容就像水,聲明Iterator就像把水倒進水杯中
//而用hasNext()等來遍歷Iterator就像把水從水杯中到倒出來
Iterator>> allneiRongIteratorName
= HashMapJiHe.entrySet().iterator();
//自己總結的遍歷Iterator的語法：
//while(Iterator名.hasNext()){
//}
while(allneiRongIteratorName.hasNext()){
//聲明一個Entry的自己總結的語法：
//Entry> Entry名
//=Iterator名.next();
Entry> EntryName
=allneiRongIteratorName.next();
//用.next()得到下一條String類型的數據
System.out.println("班級為"+EntryName.getKey());
System.out.println("具體的學生信息為");
//這里情形的自己總結的for遍歷集合的語法：
//Entry名.getValue()這里為ArrayList集合
//for(類名 要打印的內容名:集合或集合名){
//System.out.println(要打印的內容名);
//}
for(studentMapArrayListClass valueNeiRong:EntryName.getValue()){
System.out.println(valueNeiRong);
}
}
}
}
//——————————————————————————————————————
class studentMapArrayListClass{
public int bianhao;
public String name;
public int age;
public String sex;
public studentMapArrayListClass(int bianhao, String name, int age,
String sex) {
super();
this.bianhao = bianhao;
this.name = name;
this.age = age;
this.sex = sex;
}
@Override
public String toString() {
return "studentMapClass [bianhao=" + bianhao + ", name=" + name
+ ", age=" + age + ", sex=" + sex + "]";
}
}
制作撲克牌發牌案例
package list;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;
public class douDiZhuFaPaiTi5 {
public static void main(String[] args) {
String[] Stringchucundepai = new String[] { "?A", "?2", "?3", "?4",
"?5", "?6", "?7", "?8", "?9", "?10", "?J", "?Q", "?K", "?A",
"?2", "?3", "?4", "?5", "?6", "?7", "?8", "?9", "?10", "?J",
"?Q", "?K", "?A", "?2", "?3", "?4", "?5", "?6", "?7", "?8",
"?9", "?10", "?J", "?Q", "?K", "?A", "?2", "?3", "?4", "?5",
"?6", "?7", "?8", "?9", "?10", "?J", "?Q", "?K" };
HashMap HSchucundejiadepai = new HashMap<>();
HashMap HSchucundeyidepai = new HashMap<>();
HashMap HSchucundebingdepai = new HashMap<>();
ArrayList yongALchucundeshuju = new ArrayList();
for (int i = 0; i < Stringchucundepai.length; i++) {
yongALchucundeshuju.add(Stringchucundepai[i]);
}
yongALchucundeshuju.add("大王");
yongALchucundeshuju.add("小王");
Random suijishu = new Random();
String fangzidawangxiaowangchongfu = null;
for (int k = 0; k < 100; k++) {
int zongpaishu = yongALchucundeshuju.size();
int yongRandomdedaodesuijishu1 = suijishu.nextInt(zongpaishu);
int yongRandomdedaodesuijishu2 = suijishu.nextInt(zongpaishu);
if (yongRandomdedaodesuijishu1 == yongRandomdedaodesuijishu2)
continue;
{
fangzidawangxiaowangchongfu = yongALchucundeshuju
.get(yongRandomdedaodesuijishu1);
yongALchucundeshuju.set(yongRandomdedaodesuijishu1,
yongALchucundeshuju.get(yongRandomdedaodesuijishu2));
yongALchucundeshuju.set(yongRandomdedaodesuijishu2,
fangzidawangxiaowangchongfu);
}
}
ArrayList yongALchucundejiadepai = new ArrayList();
ArrayList yongALchucundeyidedepai = new ArrayList();
ArrayList yongALchucundebingdepai = new ArrayList();
ArrayList yongALchucundedipai = new ArrayList();
for (int i = 0; i < yongALchucundeshuju.size(); i++) {
if (i >= yongALchucundeshuju.size() - 3) {
yongALchucundedipai.add(yongALchucundeshuju.get(i));
} else if (i % 3 == 0) {
yongALchucundejiadepai.add(yongALchucundeshuju.get(i));
} else if (i % 3 == 1) {
yongALchucundeyidedepai.add(yongALchucundeshuju.get(i));
} else if (i % 3 == 2) {
yongALchucundebingdepai.add(yongALchucundeshuju.get(i));
}
}
System.out.println("底牌：" + yongALchucundedipai);
System.out.println("甲被發到的牌：" + yongALchucundejiadepai);
System.out.println("乙被發到的牌：" + yongALchucundeyidedepai);
System.out.println("丙被發到的牌：" + yongALchucundebingdepai);
}
}
總結
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