Question

我正在编写一个方法，一旦调用该方法，就会在mSize数组中向上移动一个空格（通过meals变量计算）。

 class Dog {

    String mSize[] = {"tiny", "small", "average", "large"};

    int dogSize;

    int meals;


    final float WEIGHT_GAIN = 0.25f;

    float mWeight;

    /*
         * feed
         *
         * Feeds the Dog.
         *
         * Side-effect: 1. The Dog gains weight, specifically WEIGHT_GAIN
         *              2. Every 3 meals, the Dog grows to a larger size, if
         *                 possible
         *                 i.e. "tiny" (3 meals later ->) "small" (3 meals later ->)
         *                 "average" (3 meals later ->) "large"
         *                 the Dog cannot exceed the "large" size or shrink smaller than
         *                 "tiny"
         * @return nothing
         */ 

    void feed(){
    mWeight += WEIGHT_GAIN;
    if (++meals == 3 && getSize()!= mSize[mSize.length-1]){

   dogSize ++;
   getSize();
    }
}

编辑：

meals必须是成员变量，而我没有使用getSize方法，该方法返回mSize[dogSize]不确定我是否应该在某处使用setSize

 /*
     * getSize
     *
     * @return the size of the dog (String)
     */
    /************************************************
     *  ASSIGNMENT:
     *  Create the getSize method
    /************************************************/
String getSize(){
    return mSize[dogSize];
}
    /*
     * setSize
     *
     * Sets the size of the Dog
     *
     * @param size the new size of the Dog (String)
     * @return nothing
     */
    /************************************************
     *  ASSIGNMENT:
     *  Create the setSize method
    /************************************************/
void setSize(String size){
    mSize[dogSize] = size;
}

主要方法测试：

// Test feed
        try {
            float weight = (Float) getWeight.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            if (((Float) getWeight.invoke(dog, new Object[0])) <= weight) {
                System.out.println("Your Dog should have gained some weight");
                System.exit(1);
            }
            feed.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            if (!"average".equals(getSize.invoke(dog, new Object[0]))) {
                System.out.println("Your Dog didn't grow to average after 3 meals :(");
                System.exit(1);     
            }
            feed.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            if (!"large".equals(getSize.invoke(dog, new Object[0]))) {
                System.out.println("Your Dog didn't grow to large after 3 more meals :(");
                System.exit(1);     
            }

            feed.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            feed.invoke(dog, new Object[0]);
            if (!"large".equals(getSize.invoke(dog, new Object[0]))) {
                System.out.println("Your Dog should stay large if it keeps feeding like this");
                System.exit(1);     
            }
        } catch (Exception e) {
            System.out.println("Something went wrong with " + feed.getName());
            System.exit(1);
        }

Answer 1

我相信你想要像

这样的东西

class Dog {
    static String mSize[] = { "tiny", "small", "average", "large" };
    int dogSize = 0;
    int meals = 0;

    void feed() {
        if (++meals % 3 == 0) {
            dogSize++;
        }
    }

    @Override
    public String toString() {
        return String.format("Weight = %.2f, Meals = %d, Size = %s",
                meals / 3.0, meals, mSize[dogSize]);
    }
}

然后测试它，比如

public static void main(String[] args) {
    Dog d = new Dog();
    for (int i = 0; i < 12; i++) {
        System.out.println(d);
        d.feed();
    }
}

输出

Weight = 0.00, Meals = 0, Size = tiny
Weight = 0.33, Meals = 1, Size = tiny
Weight = 0.67, Meals = 2, Size = tiny
Weight = 1.00, Meals = 3, Size = small
Weight = 1.33, Meals = 4, Size = small
Weight = 1.67, Meals = 5, Size = small
Weight = 2.00, Meals = 6, Size = average
Weight = 2.33, Meals = 7, Size = average
Weight = 2.67, Meals = 8, Size = average
Weight = 3.00, Meals = 9, Size = large
Weight = 3.33, Meals = 10, Size = large
Weight = 3.67, Meals = 11, Size = large

一旦计数器达到某个值，就通过数组递增

1 个答案: