for 循环联系题

计算0-50的奇数和偶数的和

package com.beijing.xiaowen.scanner;

public class Test01 {
    public static void main(String[] args) {
        //计算0-50的奇数和偶数的和
        int a = 0;
        int b = 0;
        for (int i = 0; i <=  50; i++) {
            if (i % 2 == 0 ){
                a+=i;
            }else {
                b+=i;
            }
        }
        System.out.println(a);
        System.out.println(b);
    }
}

打印0-100，能被3整除的数字，每行打印3个

package com.beijing.xiaowen.scanner;

public class Test02 {
    public static void main(String[] args) {
        //打印0-100，能被3整除的数字，每行打印3个
        for (int i = 1; i < 100; i++) {
            if (i%3==0){
                System.out.print(i+"\t");
            }
            if (i%9==0) {
                System.out.println();
            }
        }
    }
}

打印九九乘法表

package com.beijing.xiaowen.scanner;

import java.util.ArrayList;

public class Test03 {
    public static void main(String[] args) {
        //打印九九乘法表
        for (int i = 1; i < 10; i++) {
            for (int i1 = 1; i1 <= i; i1++) {
                System.out.print(i1+"*"+i+"="+i*i1+"\t");
            }
            System.out.println();
        }

    }

}

打印三角形 5行

package com.beijing.xiaowen.scanner;

public class Test04 {
    public static void main(String[] args) {
        //打印三角形 5行
        for (int i = 1; i <= 5; i++) {
            for (int i1 = 5; i1 >i; i1--) {
                System.out.print(" ");
            }
            for (int i1 = 0; i1 < i; i1++) {
                System.out.print("*");
            }
            for (int i1 = 1; i1 < i; i1++) {
                System.out.print("*");
            }
            System.out.println();
        }

    }
}