struct-ForDemo01-05

package com.kuang.struct;
//=====================
//Demo01
//=====================
public class ForDemo01 {
    public static void main(String[] args) {
        int a=1;//初始化条件
        while (a<=100){//条件判断
            System.out.println(a);//循环体
            a+=2;//迭代
        }
        System.out.println("While循环结束!");

        //======================
        System.out.println("====================");
        //======================

        //初始化条件//条件判断//循环体
        for (int i=1; i<=100; i++){
            System.out.println(i);
        }
        System.out.println("for循环结束!");
    }


}

package com.kuang.struct;
//=====================
//Demo02
//=====================
public class ForDemo02 {
    public static void main(String[] args) {
        //练习1:  计算0~100之间的奇数和偶数的和

        int oddSum = 0;
        int evenSum = 0;

        for (int i = 0; i <= 100; i++) {
            if (i%2 != 0){  //奇数
                oddSum+=i;
            }else {         //偶数
                evenSum+=i;
            }
        }

        System.out.println("奇数的和:" + oddSum);
        System.out.println("偶数的和:" + evenSum);
    }
}

package com.kuang.struct;
//=====================
//Demo03
//=====================
public class ForDemo03 {
    public static void main(String[] args) {
        //练习2: 用while或for循环输出1~1000之间能被5整除的数, 并且每行输出3个
        int a = 0;
        for (int i = 0; i <= 1000; i++) {
            if(i%5==0){
                a++;
                System.out.print(i+"\t");
                }
            if (i%(5*3)==0){//换行
                System.out.println();
            }
        }
    }
}

package com.kuang.struct;
//=====================
//Demo04
//=====================

/*
    1*1=1
    2*1=2    2*2=4
    3*1=3    3*2=6    3*3=9
    4*1=4    4*2=8    4*3=12    4*4=16
    5*1=5    5*2=10    5*3=15    5*4=20    5*5=25
    6*1=6    6*2=12    6*3=18    6*4=24    6*5=30    6*6=36
    7*1=7    7*2=14    7*3=21    7*4=28    7*5=35    7*6=42    7*7=49
    8*1=8    8*2=16    8*3=24    8*4=32    8*5=40    8*6=48    8*7=56    8*8=64
    9*1=9    9*2=18    9*3=27    9*4=36    9*5=45    9*6=54    9*7=63    9*8=72    9*9=81
*/

public class ForDemo04 {
    public static void main(String[] args) {
        for (int j = 0; j <= 9; j++) {
            for (int i = 1; i <= j; i++) {
                System.out.print(j + "*" + i + "=" + (j * i) + "\t");
            }
            System.out.println();
        }
    }
}

 

package com.kuang.struct;
//=====================
//Demo05
//=====================
public class ForDemo05 {
    public static void main(String[] args) {
        int[] numbers = {10, 20, 30, 40, 50};//定义了一个个数组

        for (int i=0; i<5; i++){
            System.out.println(numbers[i]);
        }

        System.out.println("===================");

        //遍历数组
        for (int x:numbers){
            System.out.println(x);
        }
    }
}