1-100所有偶数的和
public class Demo01 {public static void main(String[] args) {int sum1 = 0;for (int a = 0; a<=100;a++){if (a % 2 == 0){sum1 += a;}}System.out.println(sum1);int i = 1;int sum = 0;while (i <= 100){if (i % 2 == 0){sum = sum + i;}i++;}System.out.println(sum);}}
1-100所有奇数的和
public class Demo02 {public static void main(String[] args) {int sum = 0;for (int i = 1;i<=100;i++){if (i % 2 ==1){sum += i;}}System.out.println(sum);int a = 1;int sum1 = 0;while (a<=100){if (a % 2 ==1){sum1 +=a;}a++;}System.out.println(sum1);}}
每行显示5个数字
//每行显示5个数字public class Demo03 {public static void main(String[] args) {int i = 1;while (i<=130){System.out.print(i+"\t");if (i % 5 ==0){System.out.println();}i++;}for (int k =1;k<=130;k++){System.out.print(k+"\t");if (k % 5 ==0){System.out.println();}}int n=1;int count=0; //用于计算输出数的个数，以便换行while(n<=1000) {if(n%5==0) { //判断i是否能被5整除System.out.print(n+"\t");//如果能被5整除，输出，并且空几格count++;}i++; //i自增，以便进行下一个数的判断if(count%3==0) { //如果输出了三个数，则可以换行System.out.println();}}int count1=0;//用于计算输出数的个数，以便换行for(int m=1;m<=1000;m++) {//设置i的初始范围，并限制为i为<=1000的数if(m%5==0) { //判断i是否能被5整除System.out.print(m+"\t");//如果能被5整除，输出，并且空几格count1++;}if(count1%3==0) { //如果输出了三个数，则可以换行System.out.println();}}}}
