Question

public static char randomLetter() {
    Random r = new Random();
    char randomChar = (char) (97 + r.nextInt(26));
    return randomChar;
}

public static Color randomColor(){
    Random rand = new Random();
    float r = rand.nextFloat();
    float g = rand.nextFloat(); 
    float b = rand.nextFloat();
    Color randomColor = new Color(r, g, b);
    return randomColor;
}

我有这两种方法。一个字母返回一个随机字母，另一个返回一个随机颜色。如何编辑这些方法，以便randomLetter()只返回一次字母而不返回两个相同的字母？

如何让randomColor()仅在RED，YELLOW，GREEN或BLUE之间返回随机颜色？

Answer 1

随机选择可以包含重复项。如果你不想要重复，你想要的就是洗牌。

这是实现此目的的一种方法。

package com.ggl.testing;

import java.awt.Color;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class ShuffleTest {

    private static boolean shuffleLetters = true;
    private static boolean shuffleColors = true;

    private static int shuffleLetterIndex = 0;
    private static int shuffleColorIndex = 0;

    private static List<Character> letters = new ArrayList<>();
    private static List<Color> colors = new ArrayList<>();

    public static void main(String[] args) {
        System.out.println(shuffleLetter());
        System.out.println(shuffleLetter());
        System.out.println(shuffleLetter());

        System.out.println(shuffleColor());
        System.out.println(shuffleColor());
        System.out.println(shuffleColor());
    }

    public static char shuffleLetter() {
        if (shuffleLetters) {
            int start = (int) 'a';
            int end = (int) 'z';
            for (int i = start; i <= end; i++) {
                letters.add(Character.valueOf((char) i));
            }
            Collections.shuffle(letters);
            shuffleLetters = false;
        }

        return letters.get(shuffleLetterIndex++);
    }

    public static Color shuffleColor() {
        if (shuffleColors) {
            colors.add(Color.RED);
            colors.add(Color.YELLOW);
            colors.add(Color.GREEN);
            colors.add(Color.BLUE);
            Collections.shuffle(colors);
            shuffleColors = false;
        }

        return colors.get(shuffleColorIndex++);
    }

}

Answer 2

改为使用TabCollection ipsTabs = new TabCollection(); ipsTabs.signHereTabs = new List<Tab>(); ipsTabs.signHereTabs.Add(new Tab() { documentId = 5, anchorString = "soc1", recipientId = "1", xPosition = 100, yPosition = 150 }); ipsTabs.signHereTabs.Add(new Tab() { documentId = 5, anchorString = "soc2", recipientId = "2", xPosition = 100, yPosition = 150 }); ipsTabs.initialHereTabs = new List<Tab>(); ipsTabs.initialHereTabs.Add(new Tab() { documentId = 5, anchorString = "ci1", recipientId = "1", xPosition = -100, yPosition = 150 }); ipsTabs.initialHereTabs.Add(new Tab() { documentId = 5, anchorString = "ci2", recipientId = "2", xPosition = -100, yPosition = 150 }); var tabstatus = template.AddTabs(ipsTabs);：

enum

随机字符和随机颜色生成器

2 个答案: