2022.3.8 循环结构

循环结构

do...whlie

  • do...while循环和while循环相似，不同的是，do...while循环至少会执行一次

  • while先判断后执行，do...while先执行后判断

  • do...while总是保证循环体会被至少执行一次

 1  package com.xing.struct;
 2  ​
 3  public class DoWhileDemo {
 4      public static void main(String[] args) {
 5          int i = 0;
 6          while (i < 0) {
 7              System.out.println(i);
 8              i++;
 9          }//不会输出
10          System.out.println("=======================");
11          do {
12              System.out.println(i);
13              i++;
14          } while (i < 0);//输出0
15  ​
16      }
17  }​

for

 1  package com.xing.struct;
 2  ​
 3  public class ForDemo04 {
 4      public static void main(String[] args) {
 5          int[] numbers = {10, 20, 30, 40, 50};
 6  ​
 7          for (int i = 0; i < numbers.length; i++) {
 8              System.out.println(numbers[i]);
 9          }
10          System.out.println("==================");
11          //增强for循环：遍历数组的元素, 相当于上面的for循环
12          for (int x : numbers) {
13              System.out.println(x);
14          }
15      }
16  }
 1  package com.xing.struct;
 2  ​
 3  public class ForDemo01 {
 4      public static void main(String[] args) {
 5          /*死循环
 6          for (; ;){
 7          }*/
 8          //计算0到100之间奇数和偶数的和
 9          int oddnum = 0;
10          int evennum = 0;
11          for (int i = 0; i < 100; i++) {
12              if (i%2==0) {
13                  evennum = evennum + i;
14              }else{
15                  oddnum = oddnum + i;
16              }
17          }
18          System.out.println("奇数之和：" + oddnum);
19          System.out.println("偶数之和：" + evennum);
20      }
21  }

 


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posted @ 2022-03-08 22:23  暴躁C语言  阅读(22)  评论(0)    收藏  举报