可能丢失精度错误Java

Question

快速问题,我发现答案接近这个,但没有任何帮助我.我希望它在小数点后面有4个数字的代码末尾打印一个百分比,当然,使用int工作.但是使用浮点数会给我一个错误.

这段代码:

import java.util.Scanner;

public class HW2johnson_pp4 {
    public static void main(String args[]) {

        Scanner keyboard = new Scanner(System.in);
        System.out.printf("How many numbers will you enter?\n");
        float[] numbers = new float[keyboard.nextFloat()];

        System.out.printf("Enter " + numbers.length + " integers, one per line:\n");

        for (int i = 0; i <= numbers.length - 1; i++) {
            numbers[i] = keyboard.nextInt();
        }

        float sum = 0;
        for (int i = 0; i <= numbers.length - 1; i++) {
            sum += numbers[i];

        }

        System.out.printf("The sum is " + sum + "\n");

        System.out.printf("The numbers are:\n");

        for (int i = 0; i <= numbers.length - 1; i++) {
            float perc = (numbers[i] / sum);
            float perct = (perc * 100);
            System.out.printf(numbers[i] + " which is " + perct + "%% of the sum.\n");
        }
    }
}

给出错误:

HW2johnson_pp4.java:8: possible loss of precision
found   : float
required: int
        float[] numbers = new float[keyboard.nextFloat()];

Answer 1

您无法创建长度为浮点值的浮点数组.也就是说,你不能拥有一个包含2.7个元素的数组.

因此,length参数中的float会变圆,导致精度损失.

你想keyboard.nextInt()在第8行和keyboard.nextFloat()第13行下面.