9.22

public class MethodOverload {
    public static void main(String[] args) {
        System.out.println("The square of integer 7 is " + square(7));
        System.out.println("\nThe square of double 7.5 is " + square(7.5));
    }
    public static int square(int x) {
        return x * x;
    }
    public static double square(double y) {
        return y * y;
    }
}

这里用了重载，方法名相同，但是参数类型不同

利用生成随机数的数学公式，编写方法生成指定数目的随机数 

import java.util.ArrayList;
import java.util.List;
public class RandomNumberGenerator {
    public static void main(String[] args) {
        int count = 1000; // 指定生成随机数的数目,1000可以换成其他
        long seed = System.currentTimeMillis(); // 使用时间作为种子
        int a = 1103515245;
        int c = 12345;
        int m = 2147483648; // 2^31，int 范围
        List<Integer> randomNumbers = generateRandomNumbers(count, seed, a, c, m);//get方法接受参数，使用循环生成随机数，然后添加到list中
        for (int randomNumber : randomNumbers) {
            System.out.println(randomNumber);
        }
    }
    public static List<Integer> generateRandomNumbers(int count, long seed, int a, int c, int m) {
        List<Integer> randomNumbers = new ArrayList<>();
        long x = seed;
        for (int i = 0; i < count; i++) {
            x = (a * x + c) % m;
            randomNumbers.add((int) x);
        }
        return randomNumbers;
    }
}