请看以下代码，你发现有什么特殊之处吗？

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;
}
}

答：两个函数的参数类型，参数个数和参数顺序都不一样。

课后习题2