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在Java中,体重和身高是一个数组,如何计算BMI

loops arrays java

user8107351 · 技术社区 · 8 年前

我在Java中有一个任务,我必须计算一个特定用户的BMI,一个用户数组,一个高度数组和一个权重数组。

作业如下:

  String[] names; // users names
                String[] familyNames; // familyNames
                int[] weight; // users weights in kilograms (kg)
                double[] height; // users height in meter (m)


                names = new String[] { "Alex", "Maria", "Anna", "Adam", "Sara", "Johan", "Frederik"};
                familyNames = new String[] {"Andersson", "Johansson", "Nordin", "Holmgren", "Svensson"};
                weight = new int[] {70, 50, 60, 50, 60, 87, 130 };
                height = new double[] { 1.80, 1.70, 1.57, 1.80, 1.69, 1.85, 1.85 };

        public static void calculateBMI(String name, String[] names, int[] weight, double[] height) {


                /*
                 * This method should be changed
                 * 
                 * Calculate and print out BMI (body mass index) for each user 
                 * BMI = weight in kg/height in meter * height in meter 
                 * 
                 * Check if the user is Underweight, Normal, Overweightor or Obese based on the BMI
                 * Underweight, when bmi is less than 18.5 
                 * Normal, when bmi is between 18.5 and 24.9 
                 * Overweight, when bmi is between 25 and 29.9
                 * Obese, when bmi is more than 30
                 * 
                 * 
                 * To check if a string is equal to another string use:
                 * stringVariable.equalsIgnoreCase(anotherStringVariable)
                 * 
                 */

            }

public static void calculateWeight(String name, String[] names, int[] weight, double[] height) {

        /*
         * This method should be changed
         * 
         * Calculate and print out the weight that the user has to loose or gain
         * 
         * Let's consider that the formula for ideal body weight is (Broca Index:):
         * Ideal Body Weight (kg) = (Height (cm) - 100) - ((Height (cm) - 100) x 10%)
         * 
         * 1 meter = 100 cm
         * 
         * 
         */
        //Your code starts here


    }// end calculateWeightLoss

double userBMI = 0;
   for(int i = 0; i < weight.length; i++){
                for(int j = 0; j < height.length; j++){
                    userBMI = weight[i]/height[j] * height[j];
                }
            }

但我觉得我没有走上正轨,因为使用的方法是:

calculateBMI("Frederik",names, weight,height); // calculate user BMI
        calculateWeight("Frederik", names, weight, height); // calculate the weight loss or gain for the user
        System.out.println("");

所以我必须在名字数组中找到“弗雷德里克”,然后计算他的体重指数。任何想法都会受到赞赏。

3 回复 | 直到 8 年前

RafaÅ Sokalski 8 年前

它在传递给方法名称时打印BMI,并与“names”数组中的名称匹配

public static void calculateBMI(String name, String[] names, int[] weight, double[] height) {

    for (int i = 0; i < names.length; i++) {
        if(names[i].equalsIgnoreCase(name))
            System.out.println(weight[i] / height[i] / height[i]);
    }
}

但这是有风险的,因为如果names数组的长度大于weight或height,它将抛出ArrayIndexOutOfBoundsException,但我假设数组的长度总是正确的。如果这些数组的长度可能不同,我建议添加一些条件

public static void calculateWeight(String name, String[] names, int[] weight, double[] height) {

    for (int i = 0; i < names.length; i++) {
        if (names[i].equalsIgnoreCase(name)) {
            double perfectWeight = ((height[i] * 100) - 100) - (((height[i] * 100) - 100) / 10);
            System.out.println("Perfect weight for that height is : " + perfectWeight);
            if(weight[i] == perfectWeight)
                System.out.println("Person has perfect weight");
            else if(weight[i] > perfectWeight)
                System.out.println("Person should lose: " + (weight[i] - perfectWeight));
            else
                System.out.println("Person should gain: " + (perfectWeight - weight[i]));
        }

    }
}

László Stahorszki 8 年前

class Person {
    private String name;
    private String familyName;
    private int weight;
    private double height;
}

在这个类中,编写一个返回BMI的方法非常简单。要创建这些实例,可以使用类似于上面答案的方法,但是,我建议您进行额外的检查,检查数组是否具有相同的大小。

MC Emperor 8 年前

首先,我不打算为您编写代码,我认为您最终应该自己编写。

作业不太准确。上面写着 “计算并打印每个用户的BMI(体重指数)” equalsIgnoreCase 方法,建议您只需要显示给定用户的BMI。
for 环在循环中,检查名称是否正确。您不需要嵌套循环,为什么要使用嵌套循环?
您可以断言所有给定的数组长度相等,因为赋值没有提到数组长度。您可能需要重新检查 familyNames ,因为它比其他数组短。

你呢想创建一个新的方法来计算实际的体重指数,并从 calculateBMI 方法:

private static double calculateActualBmi(int weigth, double height) {
    return ...; // perform calculation
}

把实际计算和描述体重指数分开。

private static String describeBmi(double bmi) {
    if (bmi < 18.5) {
        return "Underweight";
    }
    else if ...
        ...
    else {
        return "Obese";
    }
}

另一种方法也一样。

进一步说明

我很惊讶作业要求你写方法 calculateBMI(String name, String[] names, int[] weight, double[] height) LÃ¡szlÃ³ Stahorszki's answer

String[] names = new String[] { "Alex", ..., "Frederik" };