好的，我非常接近解决方案，但我无法弄清楚这一点。出于某种原因，我的代码不会生成随机年龄，高度，权重等。此外，我收到错误“非静态方法getBodyMassIndex（）无法从静态上下文行43＆amp; 45中引用。我已经做了研究并阅读了错误是因为我需要创建一个实例来应用它，但我迷失了。我以为我已经做到了，我无法得到任何工作。这基本上是一个自学的java课程，我真的任何帮助都非常感谢!!代码如下：
package classlab3b;
import classlab3B.BodyMassIndex;
import java.text.DecimalFormat;
import java.util.Random;
import java.util.Scanner;
/**
*
* @author ccity
*/
public class ClassLab3B {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
System.out.println("Please enter the number of people:");
//asks user to input number of people
int numberOfPeople;
//declares integer variable for number of people
Scanner input = new Scanner(System.in);
//creates system input scanner
numberOfPeople = input.nextInt();
//captures user input for number of people
BodyMassIndex[] a = new BodyMassIndex[numberOfPeople];
//creates an array of BodyMassIndex the size of numberOfPeople
String name = loadRandomNames(a);
//loads object with random name
int age = loadRandomAges(a, numberOfPeople);
//loads object with random age
double weight = loadRandomWeights(a);
//loads object with random weight
double height = loadRandomHeights(a);
//loads object with random height
createObjectsToFillArray(a, name, age, weight, height, numberOfPeople);
//creates "x" objects to fill the array
double BMI = BodyMassIndex.getBodyMassIndex();
//gets BMI from getBodyMassIndex method in BodyMassIndex.java
String status = BodyMassIndex.getStatus();
//gets status from getStatus method in BodyMassIndex.java
//double BMI = BodyMassIndex.bmix.getBodyMassIndex();
//String status = BodyMassIndex.bmix.getStatus();
printArray(a, name, age, weight, height, BMI, status);
//prints array
System.out.println(" ");
System.out.println("Current Population");
System.out.println(" ");
System.out.println("Obese: " + BodyMassIndex.numberOfObese);
System.out.println("Overweight: " + BodyMassIndex.numberOfOverweight);
System.out.println("Normal: " + BodyMassIndex.numberOfNormal);
System.out.println("Underweight: " + BodyMassIndex.numberOfUnderweight);
System.out.println("================");
System.out.println("Total: " + BodyMassIndex.totalNumberOfPeople);
}
public static void createObjectsToFillArray(BodyMassIndex[] data, String name, int age, double weight, double height, int numberOfPeople) {
for (int i = 0; i < numberOfPeople; i++) {
data[i] = new BodyMassIndex(name, age, weight, height);
}
//creates new BodyMassIndex objects with generated variables from methods within
}
public static String loadRandomNames(BodyMassIndex[] data) {
String[] arrayOfFirstNames = {"Joe", "Donna", "Ronald", "Sarah", "David", "Courtney", "Irwin", "Linda", "Michael", "Cindy", "Tom", "Rebekah", "Todd", "Tracy", "Peter", "Nicole", "Marcelo", "Jennifer", "Rick", "Andrea", "Bruce", "Jaclyn", "Doug", "Shirley", "Steve", "Liz", "Waldo", "Theresa", "Scott", "Colby", "Beth", "Larry", "Emily", "Paul", "Kate", "Sam", "Dianne", "Dustin", "Alethea", "Wayne", "Kristina", "Christian", "Danny", "Breya", "Andrew", "Alison", "Tim", "Mary", "Chris", "Susie", "Jeremy", "Willy", "Jessica", "Marcus", "Kelly", "Kyle", "Stephanie", "Isaiah", "Hillary", "Eric", "Julia", "Donald", "Meredith", "Kevin", "Leslie", "Blake", "Angela", "Cliff", "Debbie", "Dylan", "Erin", "Alex", "Monica", "Nathan", "Wendy", "Josh", "Megan", "Adam", "Michelle", "Carey", "Ashley", "Brian", "Jason", "Melanie", "Jim", "Monica", "Jamie", "Rhonda", "Steven", "Perry", "Byron", "Laura", "Harry", "Brooke", "Drew", "Vicki", "Gary", "Anita", "Felipe", "Josie"};
String[] arrayOfLastNames = {"Smith", "Johnson", "Williams", "Jones", "Brown", "Davis", "Miller", "Wilson", "Moore", "Taylor", "Washington", "Jefferson", "Lincoln", "Hamilton", "Jackson", "Grant", "Franklin", "McKinley", "Cleveland", "Madison", "Chase", "Nicholson", "Fauver", "Doe", "Southard", "Schmidt", "Hodson", "McDonald", "Stickley", "Miller", "Combs", "Bohus", "Krippner", "Amtower", "Banks", "Wallace", "Bannister", "Dehaven", "Yost", "Still", "Timbrook", "Peters", "Vaught", "Shellhammer", "Andrews", "Krippner", "McAlister", "Wright", "Kensinger", "McClellan", "Ganoe", "Shiley", "Layman", "Gearhart", "Yost", "Kushnir", "Bush", "Lowder", "Connolly", "Lowman", "Terveen", "Staton", "Settle", "Tinsman", "Nichols", "Baker", "Walters", "Dawe", "Renner", "Michaels", "Faircloth", "Looker", "Hastings", "Vaughan", "Anderson", "Zimmerman", "Deere", "Daher", "Lauck", "Stottlemyer", "Clinton", "Obama", "Reagan", "Montgomery", "Pugh", "Gavis", "Clark", "Bowers"};
String first = get(arrayOfFirstNames);
String last = get(arrayOfLastNames);
String name = first + " " + last;
return name;
}
public static String get(String[] array) {
Random generator = new Random();
int rnd = generator.nextInt(array.length);
return array[rnd];
}
public static int loadRandomAges(BodyMassIndex[] data, int numberOfPeople) {
double min = 13;
double max = 99;
int age = 0;
for (int i = 0; i < numberOfPeople; i++) {
age = (int) randomInt(min, max);
}
return age;
}
public static double randomInt(double min, double max) {
double random = (double) ((max - min + 1) * Math.random() + min);
return random;
}
public static double loadRandomWeights(BodyMassIndex[] data) {
double min = 100;
double max = 300;
double weight = randomInt(min, max);
for (int row = 0; row < data.length; row++) {
}
return weight;
}
public static double loadRandomHeights(BodyMassIndex[] data) {
double min = 55;
double max = 80;
double height = randomInt(min, max);
for (int row = 0; row < data.length; row++) {
}
return height;
}
public static void printArray(BodyMassIndex[] data, String name, int age, double weight, double height, double BMI, String status) {
System.out.println(" Name " + "Age " + "Height " + "Weight " + "BMI " + "Status");
for (int i = 0; i < data.length; i++) {
DecimalFormat format = new DecimalFormat();
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);
System.out.println(name + " " + age + " " + format.format(height) + " " + format.format(weight) + format.format(BMI) + " " + status);
}
}
}
这是BodyMassIndex.java代码：
package classlab3B;
/**
*
* @author Liz
*/
public class BodyMassIndex {
private String name;
private int age;
private double weight;
private double height;
public static final double OBESE_BMI = 30.0;
public static final double OVERWEIGHT_BMI = 25.0;
public static final double NORMAL_BMI = 18.5;
public static int numberOfObese;
public static int numberOfOverweight;
public static int numberOfNormal;
public static int numberOfUnderweight;
public static int totalNumberOfPeople;
public static void main(String[] args) {
BodyMassIndex bmi1 = new BodyMassIndex("John Doe", 18, 145, 70);
//BodyMassIndex bmix = new BodyMassIndex(ClassLab3B.name, ClassLab3B.age, ClassLab3B.weight, ClassLab3B.height);
System.out.println("The BMI for " + bmi1.getName() + " is " + bmi1.getBodyMassIndex() + " " + bmi1.getStatus());
System.out.println(" ");
System.out.println(" ");
System.out.println("Current Population");
System.out.println(" ");
System.out.println("Obese: " + numberOfObese);
System.out.println("Overweight: " + numberOfOverweight);
System.out.println("Normal: " + numberOfNormal);
System.out.println("Underweight: " + numberOfUnderweight);
System.out.println("================");
System.out.println("Total: " + totalNumberOfPeople);
}
public BodyMassIndex(String name, int age, double weight, double height) {
this.name = name;
this.age = age;
this.weight = weight;
this.height = height;
totalNumberOfPeople++;
}
public double getBodyMassIndex() {
double bmi = ((weight * 703) / (height * height));
return Math.round(bmi * 100) / 100.0;
}
public String getStatus() {
double bmi = getBodyMassIndex();
if (bmi < 16) {
numberOfUnderweight++;
return "seriously underweight";
} else if (bmi < 18) {
numberOfUnderweight++;
return "underweight";
} else if (bmi < 24) {
numberOfNormal++;
return "normal weight";
} else if (bmi < 29) {
numberOfOverweight++;
return "overweight";
} else if (bmi < 35) {
numberOfObese++;
return "grossly overweight";
} else {
numberOfObese++;
return "gravely overweight";
}
}
@Override
public String toString() {
return "BodyMassIndex{" + "name=" + name + ", age=" + age + ", weight=" + weight + ", height=" + height + '}';
}
public String getName() {
return name;
}
}
答案 0 :(得分：1)
double BMI = BodyMassIndex。 getBodyMassIndex（）; String status = BodyMassIndex。 getStatus（）;
这两种方法正在做什么 你已经将这2个方法创建为非静态但使用类名调用。如果你将这两个方法创建为静态，那么在这个2方法中你也使用非静态变量。
double [] BMI = new double [numberOfPeople];
String [] status = new String [numberOfPeople];
for（int i = 0; i＆lt; = numberOfPeople-1; i ++）{
BMI [I] = A [1] .getBodyMassIndex（）;
状态[I] = A [1] .getStatus（）;
}
public static void printArray（BodyMassIndex [] data，String name，int age，double weight，double height，double [] BMI，String [] status）
答案 1 :(得分：0)
public double getBodyMassIndex()标记为static - 您实际上不需要BodyMassIndex的实例来调用该方法，因为您不在其中使用任何成员数据。所以，这个方法的签名应该是：
public static double getBodyMassIndex() {...}
在某个范围内获取Integer的标准模式是：
Min +（int）（Math.random（）*（（Max - Min）+ 1））
java Math库函数Math.random()生成[0,1]范围内的double值。请注意，此范围不包括1。
为了首先获得特定范围的值，您需要乘以您想要覆盖的值范围的大小。
Math.random() * ( Max - Min )
返回[0,Max-Min)范围内的值。
如果你想要[5,10]，你需要覆盖5个整数值，所以你使用：
Math.random() * 5
这将返回[0,5)
现在您需要将此范围向上移动到您定位的范围。您可以通过添加最小值来完成此操作。
Min + (Math.random() * (Max - Min))
您现在将获得[Min,Max)范围内的值。按照我们的示例，这意味着[5,10)：
5 + (Math.random() * (10 - 5))
但是，这仍然不包括Max，你得到的是双倍价值。为了获得Max值，您需要在范围参数(Max - Min)中加1，然后通过强制转换为int来截断小数部分。这是通过以下方式完成的：
Min + (int)(Math.random() * ((Max - Min) + 1))
你有它。 [Min,Max]范围内的随机整数值，或每个示例[5,10]
5 + (int)(Math.random() * ((10 - 5) + 1))
从here
被盗 祝你好运！答案 2 :(得分：0)
是的，您无法从名为ClassLab3B的类中访问BodyMassIndex.getBodyMassIndex();和BodyMassIndex.getStatus();，因为这两种方法不是静态的。
如果你让它们变为静态，你将无法访问你的类BodyMassIndex的非静态成员..
所以你可以从createObjectsToFillArray（）返回BodyMassIndex []，然后访问for循环中的每个实例并调用printArray()
类似这样的事情
BodyMassIndex[] x= createObjectsToFillArray(a, name, age, weight, height, numberOfPeople);
//creates "x" objects to fill the array
for(int i=0;i<x.length;i++)
{
double BMI = x[i].getBodyMassIndex();
//gets BMI from getBodyMassIndex method in BodyMassIndex.java
String status = x[i].getStatus();
//gets status from getStatus method in BodyMassIndex.java
//double BMI = BodyMassIndex.bmix.getBodyMassIndex();
//String status = BodyMassIndex.bmix.getStatus();
printArray(a, name, age, weight, height, BMI, status);
}
和
public static BodyMassIndex[] createObjectsToFillArray(BodyMassIndex[] data, String name, int age, double weight, double height, int numberOfPeople) {
for (int i = 0; i < numberOfPeople; i++) {
data[i] = new BodyMassIndex(name, age, weight, height);
}
return data;
//creates new BodyMassIndex objects with generated variables from methods within
}
答案 3 :(得分：-1)
您需要BodyMassIndex的实例：
BodyMassIndex bmi = new BodyMassIndex(...)
double BMI = bmi.getBodyMassIndex();
使用它的方式意味着在BMI类中将方法声明为静态方法。喜欢：
public static double getBodyMassIndex() {...}
但这不是一个很棒的设计。