Java学习 day02 自我练习

public class  Day01test {
    public static void main(String[] args) {
        helloword();//第二题
        System.out.println("----------------------");
        star();//第三题
        System.out.println("----------------------");
        sanjiao();//第四题
        /*注释多行用*和/的,注释单行用两个/(第五题)*/
        System.out.println("----------------------");
        zhengsanjiao();
        System.out.println("----------------------");
//        求两个数的和,函数
        System.out.println(sum(3, 5));
        System.out.println("----------------------");
//        比较两个整数是否相等
        System.out.println(compera(3,3));
        System.out.println("----------------------");
//        求一个数的累加
        System.out.println(getsum(100));
        System.out.println("----------------------");
//        求一个数内的所有奇数的个数
        System.out.println(jishucount(126));
        System.out.println("----------------------");
//        奇数个数函数重载
        System.out.println(jishucount(126));
    }

    public static void helloword() {
        for (int x = 0; x < 4; x++) {
            System.out.println("Hello World!");
        }
    }


    public static void star() {
        for (int y = 0; y < 4; y++) {
            System.out.println("*");
        }
    }

    public static void sanjiao() {
        for (int x = 0; x < 5; x++) {
            for (int y = x; y < 5; y++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

    public static void zhengsanjiao()
    {
        for (int i = 0; i < 5; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

    public static int sum(int a, int b)
    {
        return (a + b);
    }

    public static boolean compera(int a,int b)
    {
        return a==b;
    }
    public static int getsum(int count)
    {
        int sum=0;
        for (int a = 1;  a<=count ; a++)
        {
              sum +=a;
        }
        return sum;
    }
    public static int jishucount(int a)
    {
        int count=0;
        for (int i = 0; i