Java中的奇怪输出

Question

我在AP计算机科学,我们刚刚学会了如何使用我们自己的静态方法.这是我使用它们的第二个程序,但这次涉及数组,我的输出非常奇怪.我希望有人可以帮我找出原因,我认为我没有正确返回结果数组.

该程序的目的是计算太阳系中所有行星的表面重力.我需要帮助的两件事是:

1. 我不知道如何使用格式化科学记数法printf(),这真的搞砸了.
2. 我的重力数组包含[D@7248989f每个数字,我无法弄清楚为什么.

---

public static double[] surfaceGravity (double[] r,double[] m) {

    double[] g = new double[r.length];

    for (int count = 0; count < r.length; count++) { 
        g[count] = (6.67 * m[count]) / (r[count] * r[count]);
    }
    return g;
}

public static void printIntro() {
    System.out.printf("%8s%17s%12s%12s%n","Planet","Diameter (km)","Mass (kg)","g (m/s^2)");
    System.out.println("-------------------------------------------------------------------");
}

public static void printData(String[] planet, double[] r, double[] m, double[] g) {
    for (int count = 0; count < r.length; count++) {
        System.out.printf("%9s%9.0f%17.6f%12.2f%n",planet[count],(r[count] * 2),m[count],g[count]);
    }
}

public static void main (String[] args) {
    //initialize arrays
    String[] planetNames = {"Mercury","Venus","Earth","Mars","Jupiter","Saturn","Uranus","Neptune"};
    //double[] mass = {1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0};
    double[] mass = {3.3E+23,4.87E+24,5.97E+24,6.42E+23,1.9E+27,5.69E+26,8.66E+25,1.03E+26};
    double[] radius = {2440000,6051000,6378000,3397000,71492000,60268000,25559000,24754000};
    double[] gravity = surfaceGravity(radius,mass);

    printIntro();
    printData(planetNames, radius, mass, gravity);
    //I added the line below to test the contest of my gravity array
    for (double grav: gravity) {
        System.out.println(gravity);
    }
}

因为我无法发布图像,所以我不知道如何让输出显示在我的计算机上.这是我的完整代码,所以只有你要看到我的输出才能将这一切都粘在一个类中并运行它.

结束:是的我是一个菜鸟,但我希望你们能帮助我.

Answer 1

我想你必须改变这个:

for (double grav: gravity) {
    System.out.println(gravity);
}

至:

for (double grav: gravity) {
    System.out.println(grav);
}

因为你想要打印元素,而不是数组.