java(Collection接口)练习06

某中学有若干学生(学生对象放在一个List中)，每个学生有一个姓名属性(String)、班级名称属性(String)和考试成绩属性(double)
某次考试结束后，每个学生都获得了一个考试成绩。遍历list集合，并把学生对象的属性打印出来
package com.oracle.test1025;

import java.util.ArrayList;
import java.util.List;

public class lianxi01 {

public static void main(String[] args) {    List<Student> list = new ArrayList<Student>();    list.add(new Student("大海燕","移动互联班",60));    list.add(new Student("傲娇","移动互联班",70));    list.add(new Student("小黑","移动互联班",80));    list.add(new Student("女神","移动互联班",90));    list.add(new Student("马冬梅","移动互联班",20));    list.add(new Student("苏老大","移动互联班",100));    for (Student student : list) {        System.out.println(student);    }}

}

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编写程序，获取命令行参数中的字符串列表，输出其中重复的字符、不重复的字符以及消除重复以后的字符列表。

package com.oracle.test1025;

import java.util.HashSet;
import java.util.Set;

public class Lianxi02 {
public static void main(String[] args) {
String str = “fanbingbing”;
System.out.println(“原字符串:”+str);

    Set<Character> set1 = new HashSet<Character>();    Set<Character> set2 = new HashSet<Character>();    Set<Character> set3 = new HashSet<Character>();    char[] cs = str.toCharArray();    for (char c : cs) {        boolean b = set1.add(c);        if(!b){            set2.add(c);        }    }    //把消除重复后的字符赋给set3    set3.addAll(set1);    //把消除重复后的字符-重复的字符 = 不重复的字符    set3.removeAll(set2);    System.out.println("======消除重复后的字符=======");    for (char c : set1) {        System.out.println(c+" ");    }    System.out.println("\n=====重复的字符======");    for (char c : set2) {        System.out.println(c+" ");    }    System.out.println("\n=====不重复的字符=======");    for (char c : set3) {        System.out.println(c+" ");    }}

}

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使用Scanner从控制台读取一个字符串，统计字符串中每个字符出现的次数，要求使用学习过的知识完成以上要求
实现思路根据Set、List、Map集合的特性完成。
package com.oracle.test1025;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class Lianxi03 {
public static void main(String[] args) {
String str = “fanbingbing”;
System.out.println(“原字符串:”+str);

    Map<Character,Integer> map = new HashMap<Character,Integer>();    char[] cs = str.toCharArray();    for (char c : cs) {        if(map.containsKey(c)){            Integer value = map.get(c);            value++;            map.put(c, value);        }else{            map.put(c, 1);        }    }    Set<Character> set = map.keySet();    for (Character c : set) {        System.out.println(c+"出现了"+map.get(c)+"次");    }}

}