JAVA(4)——数字相加

public class ShuZiXiangJia {public static void main(String[] args) {// TODO Auto-generated method stubdouble sum1 = 0, sum2 = 0, sum3 = 0;//sum1 = 1+2+3+4....+100for(int i = 1;i <= 100;i++){sum1 += i;}//sum2 = 2 + 4+6+ 8+...+100for(int j = 0;j <= 100;j += 2){sum2 += j;}//sum3 = 1+3+5+7+...+99for(int k = 1;k <= 100;k += 2){sum3 += k;}System.out.println("sum1 = "+sum1);System.out.println("sum2 = "+sum2);System.out.println("sum3 = "+sum3);}}

运行结果：

                sum1 = 5050.0
sum2 = 2550.0
sum3 = 2500.0