For循环详解

package zaiyang.struct;

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");

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

package zaiyang.struct;

public class ForDemo02 {
    public static void main(String[] args) {
        //练习1：计算0到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;  //oddSum = oddSum + i;
            } else {//偶数
                evenSum+=i;
            }
        }
        System.out.println("奇数的和:" +oddSum);
        System.out.println("偶数的和:"+evenSum);
    }
}

package zaiyang.struct;

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

        for (int i = 0; i <= 1000; i++) {
            if (i % 5 == 0) {
                System.out.print(i + "\t");
            }
            if (i % (5 * 3) == 0) {//每行3个
                System.out.println();
                //System.out.println("\n");
            }
        }
        //println 输出完会换行
        //print 输出完不会换行
    }
}