58-60.分支结构java

public class Test {  
   
   public static void main(String args[]){  
      int x = 10;  
   
      if( x < 20 ){  
         System.out.print("这是 if 语句");  
      }  
   }  
}  

public class Test {  
   
   public static void main(String args[]){  
      int x = 30;  
   
      if( x < 20 ){  
         System.out.print("这是 if 语句");  
      }else{  
         System.out.print("这是 else 语句");  
      }  
   }  
}  

public class Test {  
   public static void main(String args[]){  
      int x = 30;  
   
      if( x == 10 ){  
         System.out.print("Value of X is 10");  
      }else if( x == 20 ){  
         System.out.print("Value of X is 20");  
      }else if( x == 30 ){  
         System.out.print("Value of X is 30");  
      }else{  
         System.out.print("这是 else 语句");  
      }  
   }  
}  

public class Test {  
   public static void main(String args[]){  
      //char grade = args[0].charAt(0);  
      char grade = 'C';  
   
      switch(grade)  
      {  
         case 'A' :  
            System.out.println("优秀");   
            break;  
         case 'B' :  
         case 'C' :  
            System.out.println("良好");  
            break;  
         case 'D' :  
            System.out.println("及格");  
         case 'F' :  
            System.out.println("你需要再努力努力");  
            break;  
         default :  
            System.out.println("未知等级");  
      }  
      System.out.println("你的等级是 " + grade);  
   }  
}