例如,我有Subscriber类及其对象subscriber1, subscriber2, subscriber3。是否可以创建一个enum包含这些对象的对象?我正在尝试这样做
enum Subscribers{
subscriber1,subscriber2,subscriber3;
}
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但我得到的是 strings subscriber1, subscriber2,subscriber3相反。如果有任何反馈,我将不胜感激
我有一个大小均匀的数字数组,这是我的任务:
a) 丢弃数组中的任意 2 个元素。b) 然后将元素配对并计算该对中元素之间的差值之和,使之和最小。
例子:
array size even say 8.
array elements : 1,3,4,6,3,4,100,200
Ans:
5
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解释:
在这里,我将删除 100 和 200,因为将它们配对后,差值为 (200 - 100) = 100。因此剩余元素为 [1,3,4,6,3,4] 具有最小总和的对为:(1 3 ) , (4 3), (6 4)。=|3-1| = 2, |4-3|=1,|6-4| = 2. 所以总和 = 2 + 1 + 2 = 5
例子:
array size even say 4.
array elements : 1,50,51,60
Ans:
1
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解释:这里我将删除 1 和 60,这样我将得到最小的总和。所以剩下的元素是 [50, 51],与相邻的 [50 51] = 1 相同。在这种情况下,我的代码将失败并返回 49。
在java中如何实现这一点呢?
我尝试像这样对元素进行排序,但这并不是适用于所有类型输入的正确方法。
public static …Run Code Online (Sandbox Code Playgroud) 下面是我的代码,用于查找给定单个字符串中所有子字符串的出现次数
public static void main(String... args) {
String fullString = "one is a good one. two is ok. three is three. four is four. five is not four";
String[] severalStringArray = { "one", "two", "three", "four" };
Map<String, Integer> countMap = countWords(fullString, severalStringArray);
}
public static Map<String, Integer> countWords(String fullString, String[] severalStringArray) {
Map<String, Integer> countMap = new HashMap<>();
for (String searchString : severalStringArray) {
if (countMap.containsKey(searchString)) {
int searchCount = countMatchesInString(fullString, searchString);
countMap.put(searchString, countMap.get(searchString) + searchCount);
} else
countMap.put(searchString, …Run Code Online (Sandbox Code Playgroud) 从事一个Java项目来研究多态性。我正在尝试学习如何从底部子级向上传递 toString() 。我必须将 Hardware.java 中的 toString 传递到 Tool.java 到 ScrewDriver.java,然后在 Player.java 中,我需要打印出我定义的数组。
这是文件:
public class Player {
public static void main(String[] args) {
List<Hardware> hardware = new ArrayList<>();
ScrewDriver screwdriver1 = new ScrewDriver("Flathead", "Use this to open paint cans", 150, "Woodworking", true, 15, 10);
hardware.add(screwdriver1);
for(Hardware tool : hardware)
System.out.print(tool);
}
}
public class Hardware {
private String name;
private String message;
private int points;
@Override
public String toString() {
super.toString();
return "Name: " + name + " Message: " …Run Code Online (Sandbox Code Playgroud) 我的问题是我需要从我的数组中找到第二个最大值,但我得到的值与第一个值相同。请帮忙
int[] nums = { 50, 6, 60, 70, 80, 90, 9, 150, 2, 35 };
int max = 0;
int secmax = 0;
for (int x = 0; x < nums.length; x++) {
if (nums[x] > max)
max = nums[x];
if (nums[x] > secmax && secmax != max)
secmax = nums[x];
}
System.out.println("1st H value: " + max);
System.out.println("2nd H Value: " + secmax);
Run Code Online (Sandbox Code Playgroud) 为什么这段代码不打印带有 a 的值"q"?
Iterator<String> it = ZoneId.getAvailableZoneIds().iterator();
while (it.hasNext()) {
if (it.next().contains("q"))
System.out.println(it.next());
}
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输出:
Pacific/Kwajalein
Etc/GMT-3
America/Martinique
Pacific/Funafuti
Canada/Pacific
Eire
America/Sitka
Brazil/West
US/Aleutian
Run Code Online (Sandbox Code Playgroud) 我创建了一个类 Car,具有这些属性和方法。我使用了一个列表来存储多个对象。
package com.company;
import java.util.ArrayList;
import java.util.Collections;
class Car implements Comparable<Car> {
private String manufacturer;
private int speed;
private double price;
private int year; // manufacture year
public Car(String manufacturer, int speed, double price, int year) {
this.manufacturer = manufacturer;
this.speed = speed;
this.price = price;
this.year = year;
}
public String getManufacturer() {
return manufacturer;
}
public int getSpeed() {
return speed;
}
public double getPrice() {
return price;
}
public int getYear() {
return year;
}
public …Run Code Online (Sandbox Code Playgroud)