Question

您好我是这个网站的新手，需要帮助我正在努力的程序。我遇到的问题是我似乎无法存储字符串和两个整数（作为坐标）。我查看了其他代码，但没有看到值的存储方式。下面是我一直在使用的代码。代码似乎没问题，但在尝试存储值时，我不能将乘法整数。谢谢你的时间

import java.util.HashMap;
public class map {

    class Coords {
        int x;
        int y;

        public boolean equals(Object o) {
            Coords c = (Coords) o;
            return c.x == x && c.y == y;
        }

        public Coords(int x, int y) {
            super();
            this.x = x;
            this.y = y;
        }

        public int hashCode() {
            return new Integer(x + "0" + y);
        }
    }

    public static void main(String args[]) {

        HashMap<Coords, Character> map = new HashMap<Coords, Character>();
        map.put(new coords(65, 72), "Dan");
    }

}

Answer 1

java中有一个名为Class Point的类。

http://docs.oracle.com/javase/7/docs/api/java/awt/Point.html

表示（x，y）坐标空间中的位置的点，以整数精度指定。

您可以在此链接中查看和示例：http://www.java2s.com/Tutorial/Java/0261__2D-Graphics/Pointclass.htm

import java.awt.Point;

class PointSetter {

  public static void main(String[] arguments) {
    Point location = new Point(4, 13);

    System.out.println("Starting location:");
    System.out.println("X equals " + location.x);
    System.out.println("Y equals " + location.y);

    System.out.println("\nMoving to (7, 6)");
    location.x = 7;
    location.y = 6;

    System.out.println("\nEnding location:");
    System.out.println("X equals " + location.x);
    System.out.println("Y equals " + location.y);
  }
}

我希望这可以帮到你！

Answer 2

似乎有几个问题：

“Dan”是String，而不是Character
案例在Java中很重要（new coords(65,72)应该是new Coords(65,72)）
Coords需要是静态的，无需引用封闭地图类的实例即可实例化。

这应该有效：

static class Coords {
    ...
}

Map<Coords, String> map = new HashMap<Coords, String>();
map.put(new Coords(65, 72), "Dan");

ps：虽然您被允许在map内命名局部变量class map，但这样的名称冲突并不是一个好主意。在Java中，类通常以大写形式开头，因此您可以重命名类Map。但事实上，Map是Java中的标准类。所以打电话给你的班级主要或测试或任何相关的。 ; - ）

Answer 3

添加到@assylias

让您inner class stati c为了插入新的对象或new Outer().new Inner()。
照顾Java Naming Convention

代码如：

public class XYTest {
    static class Coords {
        int x;
        int y;

        public boolean equals(Object o) {
            Coords c = (Coords) o;
            return c.x == x && c.y == y;
        }

        public Coords(int x, int y) {
            super();
            this.x = x;
            this.y = y;
        }

        public int hashCode() {
            return new Integer(x + "0" + y);
        }
    }

    public static void main(String args[]) {

        HashMap<Coords, String> map = new HashMap<Coords, String>();

        map.put(new Coords(65, 72), "Dan");

        map.put(new Coords(68, 78), "Amn");
        map.put(new Coords(675, 89), "Ann");

        System.out.println(map.size());
    }
}

Answer 4

package Lecture3;

import java.util.Scanner;

public class lecture9 {

    private int nInleste;

    public lecture9() {/*
                         * tabell/ // T/*chapter 6 in the books.
                         **/
    }

    public static void main(String[] args) {
        Scanner inn = new Scanner(System.in);
        int nInleste = 3;
        double[] tall = new double[nInleste];
        double sum = 0;
        for (int i = 0; i < nInleste; i++) {
            System.out.println("Leste en tall!");
            tall[i] = inn.nextDouble();
            sum += tall[i];
        }
        System.out.println(sum);
        double snitt = nInleste / nInleste;
        System.out.println("Gjennomsnittsverdien:" + snitt);
        for (int i = 0; i < nInleste; i++) {
            double aavik = tall[i] - snitt;
            int avvivk = 0;
            System.out.println(i + 1 + " Tal sitt avvik fra gjennomsnittet " + avvivk);

        }
    }/* end of the main methods */

}

Answer 5

如果您的代码有问题，可以尝试使用这个简单的代码将两个int值存储到map

class MyCoord{
    private int X;
    private int Y;

    public MyCoord() {
        this(0,0);
    }        
    public MyCoord(int X, int Y) {
        this.X = X;
        this.Y = Y;
    }
    public int getX() {
        return X;
    }
    public int getY() {
        return Y;
    }
    public void setX(int X) {
        this.X = X;
    }
    public void setY(int Y) {
        this.Y = Y;
    }
}

//主要课程开始

public class  PointDemo{
    public static void main(String[] args) {

        Map <String,MyCoord> multiplePoints=new HashMap<String, MyCoord>();
        multiplePoints.put("point1", new MyCoord(10, 20));
        multiplePoints.put("point2", new MyCoord(100, 2000));

        MyCoord coord=multiplePoints.get("point1");
        System.out.println(coord.getX() +" : "+coord.getY());              
    }
}

存储X和Y坐标

5 个答案: