一、Set
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class Demo01 {
public static void main(String[] args) {
// 实例化
Set<Integer> set=new HashSet();
set.add(123);
set.add(456);
set.add(178123);
// 遍历
Iterator iter=set.iterator();
while (iter.hasNext()){
Object obj=iter.next();
int i=Integer.parseInt(obj+"");
System.out.print(i+"\t");
}
System.out.println();
for (int i:set
) {
System.out.print(i+"\t");
}
}
}
二、List
public class Student {
private int id;
private String name;
private int age;
private String sex;
private float grade;
public Student(){}
public Student(int id,String name,int age,String sex,float grade){
this.id=id;
this.name=name;
this.age=age;
this.sex=sex;
this.grade=grade;
}
public int getId() {
return this.id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return this.age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return this.sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public float getGrade() {
return this.grade;
}
public void setGrade(float grade) {
this.grade = grade;
}
}
import java.util.ArrayList;
import java.util.List;
public class MyClass {
private String className;
public List<Student> student=new ArrayList<Student>();
public MyClass(){}
public MyClass(String className){
this.className=className;
}
public String getClassName() {
return this.className;
}
public void setClassName(String className) {
this.className = className;
}
public List<Student> getStudent() {
return student;
}
public void setStudent(List<Student> student) {
this.student = student;
}
}
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class Demo05 {
public static void main(String[] args) {
List<Myclass> list=new ArrayList<>();
Myclass mc1=new Myclass("Java一班");
mc1.myObj.add(new Myobject(1,"张三1",18,"男",88));
mc1.myObj.add(new Myobject(2,"张三2",20,"女",99));
mc1.myObj.add(new Myobject(3,"张三3",18,"男",88));
list.add(mc1);
Myclass mc2=new Myclass("C++一班");
mc2.myObj.add(new Myobject(1,"李四1",18,"男",88));
mc2.myObj.add(new Myobject(2,"李四2",20,"女",99));
mc2.myObj.add(new Myobject(3,"李四3",18,"男",88));
list.add(mc2);
Myclass mc3=new Myclass("C#一班");
mc3.myObj.add(new Myobject(1,"王五1",18,"男",88));
mc3.myObj.add(new Myobject(2,"王五2",20,"女",99));
mc3.myObj.add(new Myobject(3,"王五3",18,"男",88));
list.add(mc3);
// System.out.println(list);
/*System.out.println("迭代器");
Iterator<Myclass> iter=list.iterator();
while(iter.hasNext()){
Myclass mc=iter.next();
System.out.println(mc.getClassName());
// System.out.println(mc.myObj);
Iterator<Myobject> iter1=mc.myObj.iterator();
while (iter1.hasNext()){
Myobject mb=iter1.next();
System.out.println(mb.getId()+"\t"+mb.getName()+"\t"+mb.getAge()+"\t"+mb.getSex()+"\t"+mb.getGrade());
}
}*/
for (Myclass mc:list
) {
System.out.println(mc.getClassName());
for (Myobject mb:mc.myObj
) {
System.out.println(mb.getId()+"\t"+mb.getName()+"\t"+mb.getAge()+"\t"+mb.getSex()+"\t"+mb.getGrade());
}
}
}
}
三、Map
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class Demo05 {
public static void main(String[] args) {
List<Myclass> list=new ArrayList<>();
Myclass mc1=new Myclass("Java一班");
mc1.myObj.add(new Myobject(1,"张三1",18,"男",88));
mc1.myObj.add(new Myobject(2,"张三2",20,"女",99));
mc1.myObj.add(new Myobject(3,"张三3",18,"男",88));
list.add(mc1);
Myclass mc2=new Myclass("C++一班");
mc2.myObj.add(new Myobject(1,"李四1",18,"男",88));
mc2.myObj.add(new Myobject(2,"李四2",20,"女",99));
mc2.myObj.add(new Myobject(3,"李四3",18,"男",88));
list.add(mc2);
Myclass mc3=new Myclass("C#一班");
mc3.myObj.add(new Myobject(1,"王五1",18,"男",88));
mc3.myObj.add(new Myobject(2,"王五2",20,"女",99));
mc3.myObj.add(new Myobject(3,"王五3",18,"男",88));
list.add(mc3);
// System.out.println(list);
/*System.out.println("迭代器");
Iterator<Myclass> iter=list.iterator();
while(iter.hasNext()){
Myclass mc=iter.next();
System.out.println(mc.getClassName());
// System.out.println(mc.myObj);
Iterator<Myobject> iter1=mc.myObj.iterator();
while (iter1.hasNext()){
Myobject mb=iter1.next();
System.out.println(mb.getId()+"\t"+mb.getName()+"\t"+mb.getAge()+"\t"+mb.getSex()+"\t"+mb.getGrade());
}
}*/
for (Myclass mc:list
) {
System.out.println(mc.getClassName());
for (Myobject mb:mc.myObj
) {
System.out.println(mb.getId()+"\t"+mb.getName()+"\t"+mb.getAge()+"\t"+mb.getSex()+"\t"+mb.getGrade());
}
}
}
}