1. 泛型类
public class Cone<E> {double height;E bottom;///只能调用object中的类public Cone(E b){bottom=b;}public void setHeight(double h){height=h;}public double computerVolume(){String s=bottom.toString();double area=Double.parseDouble(s);return 1.0/3.0*area*height;}
}public class Rect {double sideA,sideB,area;Rect(double a,double b){sideA=a;sideB=b;}public String toString(){area=sideA*sideB;return " "+area;}}public class Circle {double area,radius;Circle(double r){radius=r;}public String toString(){area=radius*radius*Math.PI;return " "+area;}}import java.util.Scanner;
public class test {public static void main(String[] args) {Circle circle=new Circle(10);Cone<Circle>coneone=new Cone<Circle>(circle);coneone.setHeight(16);System.out.println(coneone.computerVolume());Rect rect=new Rect(15,23);Cone<Rect>coneTwo=new Cone<Rect>(rect);coneTwo.setHeight(98);System.out.println(coneTwo.computerVolume());}}
2.集合
import java.util.Scanner;
import java.util.*;
public class test {public static void main(String[] args) {List<String>list=new LinkedList<String>();for(int i=0;i<=6;i++){list.add("speed"+i);}Iterator<String>iter=list.iterator();while(iter.hasNext()){String te=iter.next();System.out.println(te);}for(int i=0;i<list.size();i++){String teString=list.get(i);System.out.println(teString);}}}
import java.util.Scanner;
import java.util.*;
public class test {public static void main(String[] args) {List<String>list=new ArrayList<String>();list.add("melon");list.add("apple");list.add("pear");list.add("banana");Collections.sort(list);for(int i=0;i<list.size();i++)System.out.println(list.get(i));}}
//从小到大
import java.util.*;
public class Student implements Comparable{//按照学生身高排序int height=0;String name;Student(String n,int h){name=n;height=h;}public int compareTo(Object b){//两个Student对象相等当且仅当二者的height值相等Student st=(Student)b;return (this.height-st.height);}}
import java.util.*;
public class test {public static void main(String[] args) {List<Student>list=new LinkedList<Student>();list.add(new Student("tmc",190));list.add(new Student("李四",188));list.add(new Student("周五",198));Iterator<Student>iter=list.iterator();System.out.println("排序前，链表中的数据");while(iter.hasNext()){Student stu=iter.next();System.out.println(stu.name+"身高:"+stu.height);}Collections.sort(list);System.out.println("排序后，链表中的数据");iter=list.iterator();while(iter.hasNext()){Student stu=iter.next();System.out.println(stu.name+"身高:"+stu.height);}Student zhaolin=new Student("zhaolin",188);int index = Collections.binarySearch(list, zhaolin,null);if(index>=0){System.out.println(zhaolin.name+"和链表中"+list.get(index).name+"身高相同");}}}
//斐波拉切数的求解
import java.util.*;
public class test {public static void main(String[] args) {Stack<Integer>stack = new Stack<Integer>();stack.push(new Integer(1));stack.push(new Integer(1));int k=1;while(k<=10){for(int i=1;i<=2;i++){Integer F1=stack.pop();int f1=F1.intValue();Integer F2=stack.pop();int f2=F2.intValue();Integer temp=new Integer(f1+f2);System.out.println(" "+temp.toString());stack.push(temp);stack.push(F2);k++;}}}}
//去除重复的数据
import java.util.*;
public class test {public static void main(String[] args) {HashSet<String>hashset=new HashSet<String>();hashset.add("two");hashset.add("one");hashset.add("four");hashset.add("one");System.out.println(hashset.size());Iterator<String>iterator=hashset.iterator();while(iterator.hasNext()){System.out.println(iterator.next());}}}
//英汉小词典
import java.util.*;
public class test {public static void main(String[] args) {HashMap<String,String>hashtable=new HashMap<String,String>();hashtable.put("grandness", "伟大");hashtable.put("swim", "游泳");hashtable.put("sparrow", "麻雀");hashtable.put("boy", "男孩");hashtable.put("sun", "太阳");Scanner in = new Scanner(System.in);while(true){System.out.print("请输入英文单词");String s=in.next();if(!s.equals("end"))System.out.printf("汉语解释是：%s\n",hashtable.get(s));else {System.out.printf("exit");break;}}}}