Java案例-求和与打印九九乘法表

package teacher01;
/**
 * 求1+3+5+7......+99的和是多少。
 * @author 奋斗蒙
 *
 */
public class he {
 public static void main(String[] args) {
 int number = 1;//初始值1，以后再+2递增上去
 int sum = 0;
 for ( ; number < 100; number+=2) {
 sum+=number;
 }
 System.out.println("1+3+5+7......+99=" +sum);
 }
 }

package teacher01;
/**
 * 打印九九乘法表：
 * 1X1=1
 * 1X2=2 2X2=4
 * 1X3=3 2X3=6 3X3=9
 * 1X4=4 2X4=8 3X4=12 4X4=16
 * 1X5=5 2X5=10 3X5=15 4X5=20 5X5=25
 * 1X6=6 2X6=12 3X6=18 4X6=24 5X6=30 6X6=36
 * 1X7=7 2X7=14 3X7=21 4X7=28 5X7=35 6X7=42 7X7=49
 * 1X8=8 2X8=16 3X8=24 4X8=32 5X8=40 6X8=48 7X8=56 8X8=64
 * 1X9=9 2X9=18 3X9=27 4X9=36 5X9=45 6X9=54 7X9=63 8X9=72 9X9=81
 * @author 奋斗蒙
 *
 */
public class NineNine {
public static void main(String[] args) {
System.out.println();
for (int i = 1; i < 10; i++) {
//判断语句里的j<i,省去下列的if语句
for (int j = 1; j < 10; j++) {
 if (j>i) break;//此处用continue也可以，只是效率低
 System.out.print(" "+j+"X"+i+"="+i*j);
 }
 System.out.println();
 }
    }
}