java方法

方法的定义和调用：

package com.zhan.method;

public class Demo01 {
    public static void main(String[] args) {
        int m =max(10,20);
        System.out.println(m);
    }
    public static int max(int a,int b){
        int num;
        if (a==b){
            System.out.println("a==b");
            return 0;
        }
        if (a>b){
            num = a;
        }else {
            num = b;
        }
        return num;
    }
}

方法的重载：

package com.zhan.method;

public class Demo02 {
    //方法的重载
    public static void main(String[] args) {
        int m =max(10,20);
        System.out.println(m);
    }
    public static int max(int a,int b){
        int num;
        if (a==b){
            System.out.println("a==b");
            return 0;
        }
        if (a>b){
            num = a;
        }else {
            num = b;
        }
        return num;
    }
    public static double max(double a,double b){
        double num;
        if (a==b){
            System.out.println("a==b");
            return 0;
        }
        if (a>b){
            num = a;
        }else {
            num = b;
        }
        return num;
    }
}

命令行传参

 可变参数

package com.zhan.method;

public class Demo03 {
    public static void main(String[] args) {
        //调用可变参数的方法
        Demo03 demo03 = new Demo03();
        demo03.text(10,20,30,40,50);
        demo03.text(new double[]{10,20,30,40});

    }
    public static void text(double...numbers){
        if (numbers.length == 0){
            System.out.println("输入的值为空");
            return;
        }
        double max =numbers[0];
        for (int i = 0; i < numbers.length; i++) {
            if (numbers[i]>max){
                max = numbers[i];
            }

        }
        System.out.println("最大的数是："+max);
    }
}

递归：

package com.zhan.method;

public class Demo04 {
    public static void main(String[] args) {
        System.out.println(f(5));
    }
    public static int f(int n){
        if (n==1){
            return 1;
        }else {
            return n*f(n-1);
        }
    }
}