小编Sha*_*r80的帖子

I am doing the exercises in the Cracking The Coding Interview book and I am trying to determine if there is a duplicate character in a string. I am using the ArrayList data structure. My method is of return type Boolean, which returns true if there is a duplicate and returns false if there is no duplicate character. I added a third return statement so the program would compile but it always returns false.

import java.util.*;

public class QuestionOneCrackingCode { …

String[] rgb = new String[3];

rgb[0] = Integer.toHexString(color.getRed());
rgb[1] = Integer.toHexString(color.getGreen());
rgb[2] = Integer.toHexString(color.getBlue());

for(String el : rgb)
{
    if(el.equals("0"))
    {
        el = "00";
    }
}

for(int i = 0; i<3; i++)
{
    if(rgb[i].equals("0"))
    {
        rgb[i] = "00";
    }
}

在上面的代码中,我根据天气评估每个索引,每个索引都是=零.但它总是在foreach循环中运行false,并且在for循环中适当时为true.谁能解释幕后发生的事情才能实现这一目标？

我没有按顺序运行它们,它们都用于演示目的.

我试图做一个智能的switch语句，而不是使用20+ if语句。我试过了

private int num;
switch(num)
{
    case 1-10:
        Return "number is 1 through 10"
        break;
    default:
        Return "number is not 1 through 10"
}

它说，案件不能相互解决。

谢谢你的帮助！

请帮忙.当我运行这个GUI时,数字会从帧中运行.有没有办法让它进入下一行？另外如何为此添加滚动条？我想让它垂直和水平滚动.

import java.io.*;
import java.util.*;
import java.lang.*;
import java.text.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class prime extends JFrame {

    public static void main(String[] args) {
        prime frame = new prime();
    }

    private TextPanel3C panel1;
    private JPanel inPanel;
    private JTextField inField;

    public prime() {
        final int width = 500;
        final int height = 500;
        setSize(width, height);
        setTitle("Find Prime Numbers");

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        panel1 = new TextPanel3C();
        add(panel1, "Center");

        inPanel = new JPanel();
        inPanel.add(new JLabel("Enter Your Number", SwingConstants.RIGHT));
        inField = new JTextField(20); …

我创建了一个名为"Player"的类,它存储每个玩家的数据.该类执行它应该执行的操作,但是当在List/Array中存储该类的多个实例时,数组或列表中的所有对象都等于最后存储的对象.

玩家类代码:

public class Player
{
    private static string player_name;
    public Player(string name)
    {
        player_name = name;
    }
    public string Name
    {
        get
        {
            return player_name;
        }
    }
}

用于创建和添加到列表的代码:

//simple string array for names;
string[] example_names = new string[] { "Mike", "Adam", "Jake" };

//creating new object and adding to list<Player>
List<Player> players = new List<Player>();
foreach (string name in example_names)
{
     Player player = new Player(name);
     players.Add(player);
}

//loop for returning the output
string output = "";
foreach …