例题讲解(重点梳理）

1. if（x<0) x=-x；                                                               

该N-S流程图为选择结构。选择结构用if开头，判断的内容用（）括起来。所有c语句都用；分号结尾。                                                                                 

2.while （x>o） x=x-1 ；                                                                              

该流程图为当型循环结构。用while开头，而与if有区别，if不能用于循环结构。                                                   

4.  main()          

 {intx;                        

 scanf("%d",&x);                              

if(x%2==0)        printf("YES");                                                                                     else printf("NO"); 

}