Help here! The getMonth method is deprecated, so I turned to this, which doesn't seem to work very well

有关任务的问题

善良的艾玛和暑假

Java 语法, 第 8 级, 课程 8

已解决

I originally tried (5 <= month && month < 8), which failed, so I turned to this.

package zh.codegym.task.task08.task0816; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.*; /* 善良的艾玛和暑假 */ public class Solution { public static HashMap<String, Date> createMap() throws ParseException { DateFormat df = new SimpleDateFormat("MMMMM d yyyy", Locale.ENGLISH); HashMap<String, Date> map = new HashMap<String, Date>(); map.put("史泰龙", df.parse("JUNE 1 1980")); map.put("Steve Jobs", df.parse("FEBRUARY 24 1955")); map.put("Elon Musk", df.parse("JUNE 28 1971")); map.put("Steve Rogers", df.parse("JULY 4 1918")); map.put("Anthony Stark", df.parse("MAY 29 1970")); map.put("Howard Stark", df.parse("AUGUST 15 1917")); map.put("Peter Parker", df.parse("AUGUST 10 2002")); map.put("Stephen Strange", df.parse("JULY 3 1930")); map.put("Bucky Barnes", df.parse("MARCH 10 1917")); map.put("Nick Fury", df.parse("JULY 4 1950")); return map; } public static void removeAllSummerPeople(HashMap<String, Date> map) throws ParseException { for (Map.Entry<String, Date> pair : map.entrySet()) { String key = pair.getKey(); DateFormat df = new SimpleDateFormat("MMMMM d", Locale.ENGLISH); String summerStart = "JUNE 1"; String summerEnd = "AUGUST 31"; if (df.parse(summerStart).before(map.get(key)) && df.parse(summerEnd).after(map.get(key))) map.remove(key); } } public static void main(String[] args) { } }

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myzi

级别 15 ，不在列表中，China

7 五月 2021, 03:24

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

/*
善良的艾玛和暑假
*/

public class Solution {
    public static HashMap<String, Date> createMap() throws ParseException {
        DateFormat df = new SimpleDateFormat("MMMMM d yyyy", Locale.ENGLISH);
        HashMap<String, Date> map = new HashMap<String, Date>();
        map.put("史泰龙", df.parse("JUNE 1 1980"));
        map.put("史泰龙2", df.parse("May 1 1980"));
        map.put("史泰龙3", df.parse("February 1 1980"));
        map.put("史泰龙4", df.parse("JUNE 1 1980"));
        map.put("史泰龙5", df.parse("JUNE 1 1980"));
        map.put("史泰龙6", df.parse("JUNE 1 1980"));
        map.put("史泰龙7", df.parse("JUNE 1 1980"));
        map.put("史泰龙8", df.parse("JUNE 1 1980"));
        map.put("史泰龙9", df.parse("JUNE 1 1980"));
        map.put("史泰龙1", df.parse("JUNE 1 1980"));
        return map;
        //在此编写你的代码
    }

    public static void removeAllSummerPeople(HashMap<String, Date> map) {
        //在此编写你的代码
        ArrayList<String> keys = new ArrayList<>();

        for(Map.Entry<String, Date> entry : map.entrySet()){
            Date date = entry.getValue();
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            int month = calendar.get(Calendar.MONTH);
            if(month >= 5 && month <= 7){
                keys.add(entry.getKey());
            }
        }

        for(String key : keys){
            map.remove(key);
        }
    }

    public static void main(String[] args) {

    }
}

Yuusha-Walter

级别 17 ，Beijing，China

20 八月 2020, 06:47

you can not remove element in foreach you can use iterator.remove() to remove element

Tim Dai

级别 17 ，Tokyo，Japan

27 七月 2020, 13:18

Okay, I don't know exactly why, but I think that it has something to do with iterator, so I changed from enhanced loop to a more traditional loop :

package zh.codegym.task.task08.task0816;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

/*
善良的艾玛和暑假
*/

public class Solution {
    public static HashMap<String, Date> createMap() throws ParseException {
        DateFormat df = new SimpleDateFormat("MMMMM d yyyy", Locale.ENGLISH);
        HashMap<String, Date> map = new HashMap<String, Date>();
        map.put("史泰龙", df.parse("JUNE 1 1980"));
        map.put("Steve Jobs", df.parse("FEBRUARY 24 1955"));
        map.put("Elon Musk", df.parse("JUNE 28 1971"));
        map.put("Steve Rogers", df.parse("JULY 4 1918"));
        map.put("Anthony Stark", df.parse("MAY 29 1970"));

        map.put("Howard Stark", df.parse("AUGUST 15 1917"));
        map.put("Peter Parker", df.parse("AUGUST 10 2002"));
        map.put("Stephen Strange", df.parse("JULY 3 1930"));
        map.put("Bucky Barnes", df.parse("MARCH 10 1917"));
        map.put("Nick Fury", df.parse("JULY 4 1950"));

        return map;
    }

    public static void removeAllSummerPeople(HashMap<String, Date> map) throws ParseException {
        Iterator<Map.Entry<String, Date>> iterator = map.entrySet().iterator();
        while (iterator.hasNext()) {
            Map.Entry<String, Date> pair = iterator.next();
            Date date = pair.getValue();
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            int month = cal.get(Calendar.MONTH);

            if ((month >= 5) && (month <= 7)) {
                iterator.remove();
            }
        }
    }

    public static void main(String[] args) {
    }
}

And it worked, just like that.

Tim Dai

级别 17 ，Tokyo，Japan

27 七月 2020, 12:54

This didn't work either.

package zh.codegym.task.task08.task0816;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

/*
善良的艾玛和暑假
*/

public class Solution {
    public static HashMap<String, Date> createMap() throws ParseException {
        DateFormat df = new SimpleDateFormat("MMMMM d yyyy", Locale.ENGLISH);
        HashMap<String, Date> map = new HashMap<String, Date>();
        map.put("史泰龙", df.parse("JUNE 1 1980"));
        map.put("Steve Jobs", df.parse("FEBRUARY 24 1955"));
        map.put("Elon Musk", df.parse("JUNE 28 1971"));
        map.put("Steve Rogers", df.parse("JULY 4 1918"));
        map.put("Anthony Stark", df.parse("MAY 29 1970"));

        map.put("Howard Stark", df.parse("AUGUST 15 1917"));
        map.put("Peter Parker", df.parse("AUGUST 10 2002"));
        map.put("Stephen Strange", df.parse("JULY 3 1930"));
        map.put("Bucky Barnes", df.parse("MARCH 10 1917"));
        map.put("Nick Fury", df.parse("JULY 4 1950"));

        return map;
    }

    public static void removeAllSummerPeople(HashMap<String, Date> map) throws ParseException {
        for (Map.Entry<String, Date> pair : map.entrySet()) {
            Date date = pair.getValue();
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            int month = cal.get(Calendar.MONTH);

            if ((month >= 5) && (month <= 7)) {
                map.remove(pair.getKey());
            }
        }
    }

    public static void main(String[] args) {
    }
}