项目1：全国各省平均寿命如图所示，请使用一维数组和方法，编写程序实现计算并输出全国平均寿命，最高平均寿命，最低平均寿命，平均寿命从高到底排序并输出。 java

在Java中，你可以创建一个一维整型数组来存储全国各省的平均寿命数据。首先，你需要初始化数组并将省份名称和平均寿命对应起来。然后，你可以定义一些方法来完成所需的功能：

public class AverageLife {
    private int[] life expectancies; // 存储平均寿命的一维数组
    private String[] provinces; // 存储省份名称

    public AverageLife(int[] lifeExpectancies, String[] provinces) {
        this.lifeExpectancies = lifeExpectancies;
        this.provinces = provinces;
    }

    // 计算并返回全国平均寿命
    public double calculateNationalAverage() {
        int sum = 0;
        for (int expectancy : lifeExpectancies) {
            sum += expectancy;
        }
        return (double) sum / lifeExpectancies.length;
    }

    // 找出最高的平均寿命
    public int findMaxLifeExpectancy() {
        int max = lifeExpectancies[0];
        for (int i = 1; i < lifeExpectancies.length; i++) {
            if (lifeExpectancies[i] > max) {
                max = lifeExpectancies[i];
            }
        }
        return max;
    }

    // 找出最低的平均寿命
    public int findMinLifeExpectancy() {
        int min = lifeExpectancies[0];
        for (int i = 1; i < lifeExpectancies.length; i++) {
            if (lifeExpectancies[i] < min) {
                min = lifeExpectancies[i];
            }
        }
        return min;
    }

    // 按照平均寿命降序排列并输出
    public void sortAndPrint() {
        int[] sortedLifeExpectancies = Arrays.copyOf(lifeExpectancies, lifeExpectancies.length);
        Arrays.sort(sortedLifeExpectancies);
        for (int i = sortedLifeExpectancies.length - 1; i >= 0; i--) {
            System.out.println(provinces[i] + ": " + sortedLifeExpectancies[i]);
        }
    }

    // 主函数用于测试
    public static void main(String[] args) {
        // 假设这里是你实际的数据填充
        int[] lifeExpectancies = {75, 80, 78, 82, 76}; // 平均寿命示例
        String[] provinces = {"省份A", "省份B", "省份C", "省份D", "省份E"}; // 省份名称示例
        AverageLife avgLife = new AverageLife(lifeExpectancies, provinces);
        System.out.println("全国平均寿命: " + avgLife.calculateNationalAverage());
        System.out.println("最高平均寿命: " + avgLife.findMaxLifeExpectancy());
        System.out.println("最低平均寿命: " + avgLife.findMinLifeExpectancy());
        avgLife.sortAndPrint();
    }
}